Indications And Dose
Giardiasis ▶BY MOUTH ▶Adult: 100 mg every 8 hours for 5–7 days l UNLICENSED USE Not licensed for use in giardiasis.
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Drug reference
Giardiasis ▶BY MOUTH ▶Adult: 100 mg every 8 hours for 5–7 days l UNLICENSED USE Not licensed for use in giardiasis.
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Avoid in psoriasis. elderly. history of psychosis Auditory disorder. care must be taken with dosage (the main side-effects of the aminoglycosides are dose-related). conditions characterised by muscular weakness (aminoglycosides may impair neuromuscular transmission). if possible, dehydration should be corrected before starting an aminoglycoside. vestibular disorder. whenever possible, parenteral treatment should not exceed 7 days
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Myasthenia gravis (aminoglycosides may impair neuromuscular transmission)
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→Appendix 1: mepacrine
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Aplastic anaemia (long term use). central nervous system stimulation (with high doses). corneal deposits. dermatosis (long term use). dizziness. exfoliative dermatitis (severe; long term use). gastrointestinal disorder. headache. hepatitis (long term use). nail discolouration. nausea (with high doses). oral discolouration. skin discolouration (long term use). toxic psychosis (transient; with high doses). urine discolouration (long term use). visual impairment. vomiting (with high doses) ▶Common or very common Skin reactions. tinnitus ▶Uncommon Nausea. vomiting ▶Rare or very rare Anaemia. azotaemia. bronchospasm. eosinophilia. fever. headache. hearing impairment. hypomagnesaemia. paraesthesia. renal impairment ▶Frequency not known Confusion. lethargy. leucopenia. nephrotoxicity. thrombocytopenia. vertigo SIDE-EFFECTS, FURTHER INFORMATION Ototoxicity and nephrotoxicity are important side-effects to consider with aminoglycoside therapy. Nephrotoxicity occurs most Infection commonly in patients with renal impairment, who may require reduced doses; monitoring is particularly important in the elderly.
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Use with caution.
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There is a risk of auditory or vestibular nerve damage in the infant when aminoglycosides are used in the second and third trimesters of pregnancy. The risk is greatest with streptomycin. The risk is probably very small with gentamicin and tobramycin, but their use should be avoided unless essential. Monitoring If given during pregnancy, serum- aminoglycoside concentration monitoring is essential.
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Excretion of aminoglycosides is principally via the kidney and accumulation occurs in renal impairment. Ototoxicity and nephrotoxicity occur commonly in patients with renal failure. ▶In adults A once-daily, high-dose regimen of an aminoglycoside should be avoided in patients with a creatinine clearance less than 20 mL/minute. ▶In children A once-daily, high-dose regimen of an aminoglycoside should be avoided in children over 1 month of age with a creatinine clearance less than 20 mL/minute/1.73 m2. Dose adjustments If there is impairment of renal function, the interval between doses must be increased; if the renal impairment is severe, the dose itself should be reduced as well. Monitoring Serum-aminoglycoside concentrations must be monitored in patients with renal impairment; earlier and more frequent measurement of aminoglycoside concentration may be required.
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▶Serum concentrations Serum concentration monitoring avoids both excessive and subtherapeutic concentrations thus preventing toxicity and ensuring efficacy. Serum-aminoglycoside concentrations should be measured in all patients receiving parenteral aminoglycosides and must be determined in obesity, if high doses are being given and in cystic fibrosis. ▶In adults Serum aminoglycoside concentrations must be determined in the elderly. In patients with normal renal function, aminoglycoside concentrations should be measured after 3 or 4 doses of a multiple daily dose regimen and after a dose change. For multiple daily dose regimens, blood samples should be taken approximately 1 hour after intramuscular or intravenous administration (‘peak’ concentration) and also just before the next dose (‘trough’ concentration). If the pre-dose (‘trough’) concentration is high, the interval between doses must be increased. If the post-dose (‘peak’) concentration is high, the dose must be decreased. For once daily dose regimens, consult local guidelines on serum concentration monitoring. ▶In children In children with normal renal function, aminoglycoside concentrations should be measured after 3 or 4 doses of a multiple daily dose regimen. Blood samples should be taken just before the next dose is administered (‘trough’ concentration). If the pre-dose (‘trough’) concentration is high, the interval between doses must be increased. For multiple daily dose regimens, blood samples should also be taken approximately 1 hour after intramuscular or intravenous administration (‘peak’ concentration). If the post-dose (‘peak’) concentration is high, the dose must be decreased. ▶Renal function should be assessed before starting an aminoglycoside and during treatment. ▶Auditory and vestibular function should also be monitored during treatment. eiiii F 543
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Forms available from special-order manufacturers include: tablet Infection Malaria page 642 5.2 Toxoplasmosis 5.3 Viral infection Coronavirus 6.1 Hepatitis 6.2 Hepatitis infections 6.3 6.3a Chronic hepatitis B 6.3b Chronic hepatitis C Herpesvirus infections 6.4 6.4a Cytomegalovirus infections HIV infection 6.5 Influenza 6.6 Respiratory syncytial virus 6.7 Bacterial infection Antibacterials, principles of therapy Antibacterial drug choice Before selecting an antibacterial the clinician must first consider three factors— the patient, the known or likely causative organism, and the risk of bacterial resistance with repeated courses. Factors related to the patient which must be considered include history of allergy, renal and hepatic function, susceptibility to infection (i.e. whether immunocompromised), ability to tolerate drugs by mouth, severity of illness, risk of complications, ethnic origin, age, whether taking other medication and, if female, whether pregnant, breast-feeding or taking an oral contraceptive. The known or likely organism and its antibacterial sensitivity, in association with the factors above, will provide one or more antibacterial option. g In patients receiving antibacterial prophylaxis, an antibacterial from a different class should be used. h Some patients may be at higher risk of treatment failure. They include those who have had repeated antibacterial courses, a previous or current culture with resistant bacteria, or those at higher risk of developing complications. Antibacterials, considerations before starting therapy The following precepts should be considered before starting: . Viral infections should not be treated with antibacterials. However, antibacterials may be used to treat secondary bacterial infection (e.g. bacterial pneumonia secondary to influenza); . Samples should be taken for culture and sensitivity testing as appropriate; ‘ blind’ antibacterial prescribing for unexplained pyrexia usually leads to further difficulty in establishing the diagnosis; . Knowledge of prevalent organisms and their current sensitivity is of great help in choosing an antibacterial before bacteriological confirmation is available. Generally, narrow-spectrum antibacterials are preferred to broad- spectrum antibacterials unless there is a clear clinical indication (e.g. life-threatening sepsis); . The dose of an antibacterial varies according to a number of factors including age, weight, hepatic function, renal function, and severity of infection. The prescribing of the so-called ‘standard’ dose in serious infections may result Infection in failure of treatment or even death of the patient; therefore it is important to prescribe a dose appropriate to the condition. An inadequate dose may also increase the likelihood of antibacterial resistance. On the other hand, for an antibacterial with a narrow margin between the toxic and therapeutic dose (e.g. an aminoglycoside) it is also important to avoid an excessive dose and the concentration of the drug in the plasma may need to be monitored; . The route of administration of an antibacterial often depends on the severity of the infection. Life-threatening infections require intravenous therapy. Antibacterials that are well absorbed may be given by mouth even for some serious infections. Parenteral administration is also appropriate when the oral route cannot be used (e.g. because of vomiting) or if absorption is inadequate. Whenever possible, painful intramuscular injections should be avoided in children; . Duration of therapy depends on the nature of the infection and the response to treatment. Courses should not be unduly prolonged because they encourage resistance, they may lead to side-effects and they are costly. However, in certain infections such as tuberculosis or osteomyelitis it may be necessary to treat for prolonged periods. The prescription for an antibacterial should specify the duration of treatment or the date when treatment is to be reviewed. For further guidance on the appropriate and effective use of antibacterials, see Antimicrobial stewardship p. 20 Advice to be given to patients and their family and/or carers If an antibacterial is given, advise patients about directions for correct use and possible side-effects using verbal and written information. If an antibacterial is not given, advise patients about an antibacterial not being needed currently—discuss alternative options as appropriate, such as self-care with over-the- counter preparations, back-up (delayed) prescribing, or other non-pharmacological interventions. Patients should be advised to seek medical help if symptoms worsen rapidly or significantly at any time, if symptoms do not start to improve within an agreed time, if problems arise as a result of treatment, or if the patient becomes systemically very unwell. For further information on advice for patients and their family and/or carers when deciding if antibacterial treatment is necessary, see Advice for patients and their family and/or carers in Antimicrobial stewardship p. 20. Antibacterials, considerations during therapy g Review choice of antibacterial if susceptibility results indicate bacterial resistance and symptoms are not improving—consult local microbiologist as needed. h If no bacterium is cultured, the antibacterial can be continued or stopped on clinical grounds. g Review intravenous antibacterials within 48 hours and consider stepping down to oral antibacterials where possible. h Superinfection In general, broad-spectrum antibacterial drugs such as the cephalosporins are more likely to be associated with adverse reactions related to the selection of resistant organisms e.g. fungal infections or antibiotic-associated colitis (pseudomembranous colitis); other problems associated with superinfection include vaginitis and pruritus ani. Notifiable diseases Registered medical practitioners must notify the Proper Officer at their local council or local health protection team of any patient(s) suspected of suffering from any of the diseases listed below; a notification form should be completed immediately. For further information on reporting notifiable diseases, see Public Health England guidance at: www.gov.uk/guidance/notifiable-diseases-and- causative-organisms-how-to-report. Anthrax Mumps Botulism Paratyphoid fever Brucellosis Plague Cholera Poliomyelitis, acute Diarrhoea (infectious bloody) Rabies Diphtheria Rubella Encephalitis, acute SARS Food poisoning Scarlet fever Haemolytic uraemic syndrome Smallpox Haemorrhagic fever (viral) Streptococcal disease (Group A, Hepatitis, viral invasive) Legionnaires’ disease Tetanus Leprosy Tuberculosis Malaria Typhoid fever Measles Typhus Meningitis Whooping cough Meningococcal septicaemia Yellow fever Note It is good practice for registered medical practitioners to report other diseases that may present a significant risk to human health. These should be done under the category ’other significant disease’. Sepsis, early management g Patients identified as being at high risk of severe illness or death due to suspected sepsis should be given a broad- spectrum antibacterial at the maximum recommended dose without delay (ideally within one hour). Microbiological samples and blood cultures must be taken prior to administration of antibiotics; the prescription should be adjusted subsequently according to susceptibility results. A thorough clinical examination should be carried out to identify sources of infection. If the source of infection is identified, treat in line with local antibacterial guidance or susceptibility results. Patients who require empirical intravenous treatment for a suspected infection, but who have no confirmed diagnosis, should be treated with an intravenous antibiotic from the local formulary and in line with national guidelines. The need for intravenous fluids, inotropes, vasopressors and oxygen should also be assessed without delay, taking into consideration the patient’s lactate concentration, systolic blood pressure, and their risk of severe illness or death. Patients at high risk should be monitored continuously if possible, and no less than every 30 minutes. Patients with suspected sepsis who are not immediately deemed to be at high risk of severe illness or death, should be re-assessed regularly for the need for empirical treatment, taking into consideration all risk factors including lactate concentration and evidence of acute kidney injury. h Antibacterials, use for prophylaxis Rheumatic fever: prevention of recurrence . Phenoxymethylpenicillin p. 578 or sulfadiazine p. 596. Invasive group A streptococcal infection: prevention of secondary cases . Phenoxymethylpenicillin. Patients who are penicillin allergic, either erythromycin p. 569 or azithromycin p. 566 [unlicensed indication]. For details of those who should receive chemoprophylaxis contact a consultant in communicable disease control (or a consultant in infectious diseases or the local Public Health England Laboratory). Meningococcal meningitis: prevention of secondary cases . Ciprofloxacin p. 590 or rifampicin p. 615 or i/m ceftriaxone p. 556 [unlicensed indication]. For details of those who should receive chemoprophylaxis contact a consultant in communicable disease control (or a consultant in infectious diseases or the local Public Health England laboratory). Unless there has been direct exposure of the mouth or nose to infectious droplets from a patient with meningococcal disease who has received less than 24 hours of antibacterial treatment, healthcare workers do not generally require chemoprophylaxis. Haemophilus influenzae type b disease: prevention of secondary cases . Rifampicin or (if rifampicin cannot be used) i/m or i/v ceftriaxone [unlicensed indication]. For details of those who should receive chemoprophylaxis contact a consultant in communicable disease control (or a consultant in infectious diseases or the local Public Health England laboratory). Unless there has been direct exposure of the mouth or nose to infectious droplets from a patient with meningococcal disease who has received less than 24 hours of antibacterial treatment, healthcare workers do not generally require chemoprophylaxis. Within 4 weeks of illness onset in an index case with confirmed or suspected invasive Haemophilus influenzae type b disease, give antibacterial prophylaxis to all household contacts if there is a vulnerable individual in the household. Also, give antibacterial prophylaxis to the index case if they are in contact with vulnerable household contacts or if they are under 10 years of age. Vulnerable individuals include the immunocompromised, those with asplenia, or children under 10 years of age. If there are 2 or more cases of invasive Haemophilus influenzae type b disease within 120 days in a pre-school or primary school, antibacterial prophylaxis should also be given to all room contacts (including staff). Also see immunisation against Haemophilus influenzae type b disease. Diphtheria in non-immune patients: prevention of secondary cases . Erythromycin (or another macrolide e.g. azithromycin or clarithromycin p. 567). Treat for further 10 days if nasopharyngeal swabs positive after first 7 days’ treatment. Pertussis, antibacterial prophylaxis . Clarithromycin (or azithromycin or erythromycin). Within 3 weeks of onset of cough in the index case, give antibacterial prophylaxis to all close contacts if amongst them there is at least one unimmunised or partially immunised child under 1 year of age, or if there is at least one individual who has not received a pertussis-containing vaccine more than 1 week and less than 5 years ago (so long as that individual lives or works with children under 4 months of age, is pregnant at over 32 weeks gestation, or is a healthcare worker who works with children under 1 year of age or with pregnant women). Pneumococcal infection in asplenia or in patients with sickle-cell disease, antibacterial prophylaxis Infection . Phenoxymethylpenicillin. If penicillin-allergic, erythromycin. Antibacterial prophylaxis is not fully reliable. Antibacterial prophylaxis may be discontinued in children over 5 years of age with sickle-cell disease who have received pneumococcal immunisation and who do not have a history of severe pneumococcal infection. Tuberculosis antibacterial prophylaxis in susceptible close contacts or those who have become tuberculin positive . See Close contacts and Treatment of latent tuberculosis under Tuberculosis p. 612. Animal and human bites, antibacterial prophylaxis . Co-amoxiclav p. 582 alone (or doxycycline p. 597 + metronidazole p. 572 if penicillin-allergic). Cleanse wound thoroughly. For tetanus-prone wound, give human tetanus immunoglobulin p. 1360 (with a tetanus- containing vaccine if necessary, according to immunisation history and risk of infection). Consider rabies prophylaxis for bites from animals in endemic countries. Assess risk of blood-borne viruses (including HIV, hepatitis B and C) and give appropriate prophylaxis to prevent viral spread. Antibacterial prophylaxis recommended for wounds less than 48–72 hours old when the risk of infection is high (e.g. bites from humans or cats; bites to the hand, foot, face, or genital area; bites involving oedema, crush or puncture injury, or other moderate to severe injury; wounds that cannot be debrided adequately; patients with diabetes mellitus, cirrhosis, asplenia, prosthetic joints or valves, or those who are immunocompromised). Give antibacterial prophylaxis for up to 5 days. Early-onset neonatal infection, antibacterial prophylaxis . i/v benzylpenicillin sodium p. 577 (or i/v clindamycin p. 564 if history of allergy to penicillins). Give intrapartum prophylaxis to women with group B streptococcal colonisation, bacteriuria, or infection in the current pregnancy, or to women who had a previous baby with an invasive group B streptococcal infection. Consider prophylaxis for women in preterm labour if there is prelabour rupture of membranes or if intrapartum rupture of membranes lasting more than 18 hours is suspected. Gastro-intestinal procedures, antibacterial prophylaxis Operations on stomach or oesophagus . Single dose of i/v gentamicin p. 545 or i/v cefuroxime p. 553 or i/v co-amoxiclav (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Add i/v teicoplanin p. 561 (or vancomycin p. 562) if high risk of meticillin-resistant Staphylococcus aureus. Open biliary surgery . Single dose of i/v cefuroxime + i/v metronidazole or i/v gentamicin + i/v metronidazole or i/v co-amoxiclav alone (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Infection Where i/v metronidazole is suggested, it may alternatively be given by suppository but to allow adequate absorption, it should be given 2 hours before surgery. Add i/v teicoplanin (or vancomycin) if high risk of meticillin-resistant Staphylococcus aureus. Resections of colon and rectum for carcinoma, and resections in inflammatory bowel disease, and appendicectomy . Single dose of i/v gentamicin + i/v metronidazole or i/v cefuroxime + i/v metronidazole or i/v co-amoxiclav alone (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Where i/v metronidazole is suggested, it may alternatively be given by suppository but to allow adequate absorption, it should be given 2 hours before surgery. Add i/v teicoplanin p. 561 (or vancomycin p. 562) if high risk of meticillin-resistant Staphylococcus aureus. Endoscopic retrograde cholangiopancreatography . Single dose of i/v gentamicin p. 545 or oral or i/v ciprofloxacin p. 590. Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Prophylaxis recommended if pancreatic pseudocyst, immunocompromised, history of liver transplantation, or risk of incomplete biliary drainage. For biliary complications following liver transplantation, add i/v amoxicillin p. 579 or i/v teicoplanin (or vancomycin). Percutaneous endoscopic gastrostomy or jejunostomy . Single dose of i/v co-amoxiclav p. 582 or i/v cefuroxime p. 553. Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Use single dose of i/v teicoplanin (or vancomycin) if history of allergy to penicillins or cephalosporins, or if high risk of meticillin-resistant Staphylococcus aureus. Orthopaedic surgery, antibacterial prophylaxis Joint replacement including hip and knee . Single dose of i/v cefuroxime alone or i/v flucloxacillin p. 586 + i/v gentamicin (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. If history of allergy to penicillins or to cephalosporins or if high risk of meticillin-resistant Staphylococcus aureus, use single dose of i/v teicoplanin (or vancomycin) + i/v gentamicin (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Closed fractures . Single dose of i/v cefuroxime or i/v flucloxacillin (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. If history of allergy to penicillins or to cephalosporins or if high risk of meticillin-resistant Staphylococcus aureus, use single dose of i/v teicoplanin (or vancomycin) (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Open fractures . Use i/v co-amoxiclav alone or i/v cefuroxime + i/v metronidazole p. 572 (or i/v clindamycin p. 564 alone if history of allergy to penicillins or to cephalosporins). Add i/v teicoplanin (or vancomycin) if high risk of meticillin- resistant Staphylococcus aureus. Start prophylaxis within 3 hours of injury and continue until soft tissue closure (max. 72 hours). At first debridement also use a single dose of i/v cefuroxime + i/v metronidazole + i/v gentamicin or i/v co- amoxiclav + i/v gentamicin (or i/v clindamycin + i/v gentamicin if history of allergy to penicillins or to cephalosporins). At time of skeletal stabilisation and definitive soft tissue closure use a single dose of i/v gentamicin + i/v teicoplanin (or vancomycin) (intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure). High lower-limb amputation . Use i/v co-amoxiclav alone or i/v cefuroxime + i/v metronidazole. Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Continue antibacterial prophylaxis for at least 2 doses after procedure (max. duration of prophylaxis 5 days). If history of allergy to penicillin or to cephalosporins, or if high risk of meticillin-resistant Staphylococcus aureus, use i/v teicoplanin (or vancomycin) + i/v gentamicin + i/v metronidazole. Where i/v metronidazole is suggested, it may alternatively be given by suppository but to allow adequate absorption, it should be given 2 hours before surgery. Urological procedures, antibacterial prophylaxis Transrectal prostate biopsy . Single dose of oral ciprofloxacin + oral metronidazole or i/v gentamicin + i/v metronidazole (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Use single dose of i/v gentamicin + i/v metronidazole if high risk of meticillin-resistant Staphylococcus aureus (additional intra-operative or postoperative doses of antibacterial may be given for prolonged procedures or if there is major blood loss). Where i/v metronidazole is suggested, it may alternatively be given by suppository but to allow adequate absorption, it should be given 2 hours before surgery. Transurethral resection of prostate . Single dose of oral ciprofloxacin or i/v gentamicin or i/v cefuroxime (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Use single dose of i/v gentamicin if high risk of meticillin- resistant Staphylococcus aureus (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Obstetric and gynaecological surgery, antibacterial prophylaxis Caesarean section . Single dose of i/v cefuroxime (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Substitute i/v clindamycin if history of allergy to penicillins or cephalosporins. Add i/v teicoplanin (or vancomycin) if high risk of meticillin-resistant Staphylococcus aureus. Hysterectomy . Single dose of i/v cefuroxime + i/v metronidazole or i/v gentamicin + i/v metronidazole or i/v co-amoxiclav alone (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Use single dose of i/v gentamicin + i/v metronidazole or add i/v teicoplanin (or vancomycin) to other regimens if high risk of meticillin-resistant Staphylococcus aureus (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Where i/v metronidazole is suggested, it may alternatively be given by suppository but to allow adequate absorption, it should be given 2 hours before surgery. Termination of pregnancy . Single dose of oral metronidazole (additional intra- operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). If genital chlamydial infection cannot be ruled out, give doxycycline p. 597 postoperatively. Cardiology procedures, antibacterial prophylaxis Cardiac pacemaker insertion . Single dose of i/v cefuroxime alone or i/v flucloxacillin + i/v gentamicin or i/v teicoplanin (or vancomycin) + i/v gentamicin (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Use single dose of i/v teicoplanin (or vancomycin) + i/v cefuroxime or i/v teicoplanin (or vancomycin) + i/v gentamicin if high risk of meticillin-resistant Staphylococcus aureus (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Vascular surgery, antibacterial prophylaxis Reconstructive arterial surgery of abdomen, pelvis or legs . Single dose of i/v cefuroxime p. 553 alone or i/v flucloxacillin p. 586+ i/v gentamicin p. 545 (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Intravenous antibacterial prophylaxis should be given up to 30 minutes before the procedure. Add i/v metronidazole p. 572 for patients at risk from anaerobic infections including those with diabetes, gangrene, or undergoing amputation. Use single dose of i/v teicoplanin p. 561 (or vancomycin p. 562) + i/v gentamicin if history of allergy to penicillins or cephalosporins, or if high risk of meticillin-resistant Staphylococcus aureus (additional intra-operative or postoperative doses may be given for prolonged procedures or if there is major blood loss). Infective endocarditis, antibacterial prophylaxis NICE guidance: Antimicrobial prophylaxis against infective endocarditis in adults and children undergoing interventional procedures (March 2008, updated 2016) . Chlorhexidine mouthwash is not recommended for the prevention of infective endocarditis in at risk patients undergoing dental procedures. Antibacterial prophylaxis is not routinely recommended for Infection the prevention of infective endocarditis in patients undergoing the following procedures: . dental; . upper and lower respiratory tract (including ear, nose, and throat procedures and bronchoscopy); . genito-urinary tract (including urological, gynaecological, and obstetric procedures); . upper and lower gastro-intestinal tract. Whilst these procedures can cause bacteraemia, there is no clear association with the development of infective endocarditis. Prophylaxis may expose patients to the adverse effects of antimicrobials when the evidence of benefit has not been proven. Any infection in patients at risk of endocarditis should be investigated promptly and treated appropriately to reduce the risk of endocarditis. If patients at risk of endocarditis are undergoing a gastro- intestinal or genito-urinary tract procedure at a site where infection is suspected, they should receive appropriate antibacterial therapy that includes cover against organisms that cause infective endocarditis. Patients at risk of infective endocarditis should be: . advised to maintain good oral hygiene; . told how to recognise signs of infective endocarditis, and advised when to seek expert advice. Patients at risk of infective endocarditis include those with valve replacement, acquired valvular heart disease with stenosis or regurgitation, structural congenital heart disease (including surgically corrected or palliated structural conditions, but excluding isolated atrial septal defect, fully repaired ventricular septal defect, fully repaired patent ductus arteriosus, and closure devices considered to be endothelialised), hypertrophic cardiomyopathy, or a previous episode of infective endocarditis. Dermatological procedures Advice of a Working Party of the British Society for Antimicrobial Chemotherapy is that patients who undergo dermatological procedures do not require antibacterial prophylaxis against endocarditis. The British Association of Dermatologists Therapy Guidelines and Audit Subcommittee advise that such dermatological procedures include skin biopsies and excision of moles or of malignant lesions. Joint prostheses and dental treatment, antibacterial prophylaxis Advice of a Working Party of the British Society for Antimicrobial Chemotherapy is that patients with prosthetic joint implants (including total hip replacements) do not require antibiotic prophylaxis for dental treatment. The Working Party considers that it is unacceptable to expose patients to the adverse effects of antibiotics when there is no evidence that such prophylaxis is of any benefit, but that those who develop any intercurrent infection require prompt treatment with antibiotics to which the infecting organisms are sensitive. The Working Party has commented that joint infections have rarely been shown to follow dental procedures and are even more rarely caused by oral streptococci. Immunosuppression and indwelling intraperitoneal catheters Advice of a Working Party of the British Society for Antimicrobial Chemotherapy is that patients who are immunosuppressed (including transplant patients) and patients with indwelling intraperitoneal catheters do not require antibiotic prophylaxis for dental treatment provided there is no other indication for prophylaxis. Infection The Working Party has commented that there is little evidence that dental treatment is followed by infection in immunosuppressed and immunodeficient patients nor is there evidence that dental treatment is followed by infection in patients with indwelling intraperitoneal catheters. Blood infections, antibacterial therapy Septicaemia (community-acquired) . A broad-spectrum antipseudomonal penicillin (e.g. piperacillin with tazobactam p. 576, ticarcillin with clavulanic acid p. 576) or a broad-spectrum cephalosporin (e.g. cefuroxime p. 553) ▶If meticillin-resistant Staphylococcus aureus suspected, add vancomycin p. 562 (or teicoplanin p. 561). ▶If anaerobic infection suspected, add metronidazole p. 572 to broad-spectrum cephalosporin. ▶If other resistant micro-organisms suspected, use a more broad-spectrum beta-lactam antibacterial (e.g. meropenem p. 549). Septicaemia (hospital-acquired) . A broad-spectrum antipseudomonal beta-lactam antibacterial (e.g. piperacillin with tazobactam, ticarcillin with clavulanic acid, ceftazidime p. 555, imipenem with cilastatin p. 548, or meropenem) ▶If meticillin-resistant Staphylococcus aureus suspected, add vancomycin (or teicoplanin). ▶If anaerobic infection suspected, add metronidazole to broad-spectrum cephalosporin Septicaemia related to vascular catheter . Vancomycin (or teicoplanin) ▶If Gram-negative sepsis suspected, especially in the immunocompromised, add a broad-spectrum antipseudomonal beta-lactam. ▶Consider removing vascular catheter, particularly if infection caused by Staphylococcus aureus, pseudomonas, or Candida species. Meningococcal septicaemia If meningococcal disease suspected, a single dose of benzylpenicillin sodium p. 577 should be given before urgent transfer to hospital, so long as this does not delay the transfer; cefotaxime p. 555 may be an alternative in penicillin allergy; chloramphenicol p. 601 may be used if history of immediate hypersensitivity reaction to penicillin or to cephalosporins. . Benzylpenicillin sodium or cefotaxime (or ceftriaxone p. 556) . If history of immediate hypersensitivity reaction to penicillin or to cephalosporins, chloramphenicol To eliminate nasopharyngeal carriage, ciprofloxacin p. 590, or rifampicin p. 615, or ceftriaxone may be used. Cardiovascular system infections, antibacterial therapy Endocarditis: initial ‘blind’ therapy . Native valve endocarditis, amoxicillin p. 579 (or ampicillin p. 581) ▶Consider adding low-dose gentamicin p. 545 ▶If penicillin-allergic, or if meticillin-resistant Staphylococcus aureus suspected, or if severe sepsis, use vancomycin p. 562 + low-dose gentamicin ▶If severe sepsis with risk factors for Gram-negative infection, use vancomycin + meropenem p. 549 . If prosthetic valve endocarditis, vancomycin + rifampicin p. 615 + low-dose gentamicin Endocarditis (native valve) caused by staphylococci . Flucloxacillin p. 586 ▶Suggested duration of treatment 4 weeks (at least 6 weeks if secondary lung abscess or osteomyelitis also present) . If penicillin-allergic or if meticillin-resistant Staphylococcus aureus, vancomycin + rifampicin ▶Suggested duration of treatment 4 weeks (at least 6 weeks if secondary lung absecess or osteomyelitis also present) Endocarditis (prosthetic valve) caused by staphylococci . Flucloxacillin + rifampicin + low-dose gentamicin ▶Suggested duration of treatment at least 6 weeks; review need to continue gentamicin at 2 weeks—seek specialist advice if gentamicin considered necessary beyond 2 weeks . If penicillin-allergic or if meticillin-resistantStaphylococcus aureus, vancomycin + rifampicin + low-dose gentamicin ▶Suggested duration of treatment at least 6 weeks; review need to continue gentamicin at 2 weeks—seek specialist advice if gentamicin considered necessary beyond 2 weeks Endocarditis caused by fully-sensitive streptococci . Benzylpenicillin sodium p. 577 ▶Suggested duration of treatment 4–6 weeks (6 weeks for prosthetic valve endocarditis) . If penicillin-allergic, vancomycin (or teicoplanin p. 561) + low-dose gentamicin ▶Suggested duration of treatment 4–6 weeks (stop gentamicin after 2 weeks) Endocarditis caused by less-sensitive streptococci . Benzylpenicillin sodium + low-dose gentamicin ▶Suggested duration of treatment 4–6 weeks (6 weeks for prosthetic valve endocarditis); review need to continue gentamicin at 2 weeks—seek specialist advice if gentamicin considered necessary beyond 2 weeks; stop gentamicin at 2 weeks if micro-organisms moderately sensitive to penicillin . If penicillin-allergic or highly penicillin-resistant, vancomycin (or teicoplanin) + low-dose gentamicin ▶Suggested duration of treatment 4–6 weeks (6 weeks for prosthetic valve endocarditis); review need to continue gentamicin at 2 weeks—seek specialist advice if gentamicin considered necessary beyond 2 weeks; stop gentamicin at 2 weeks if micro-organisms moderately sensitive to penicillin Endocarditis caused by enterococci . Amoxicillin (or ampicillin) + low dose gentamicin or benzylpenicillin sodium + low-dose gentamicin ▶Suggested duration of treatment 4–6 weeks (6 weeks for prosthetic valve endocarditis); review need to continue gentamicin at 2 weeks—seek specialist advice if gentamicin considered necessary beyond 2 weeks . If penicillin-allergic or penicillin-resistant, vancomycin (or teicoplanin) + low-dose gentamicin ▶Suggested duration of treatment 4–6 weeks (6 weeks for prosthetic valve endocarditis); review need to continue gentamicin at 2 weeks—seek specialist advice if gentamicin considered necessary beyond 2 weeks . If gentamicin resistant, amoxicillin (or ampicillin) ▶Add streptomycin p. 546 (if susceptible) for 2 weeks ▶Suggested duration of treatment at least 6 weeks Endocarditis caused by Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella species (‘HACEK’ micro-organisms) . Amoxicillin (or ampicillin) + low-dose gentamicin ▶Suggested duration of treatment 4 weeks (6 weeks for prosthetic valve endocarditis); stop gentamicin after 2 weeks . If amoxicillin -resistant, ceftriaxone p. 556 (or cefotaxime p. 555) + low-dose gentamicin ▶Suggested duration of treatment 4 weeks (6 weeks for prosthetic valve endocarditis); stop gentamicin after 2 weeks Central nervous system infections, antibacterial therapy Meningitis: initial empirical therapy . Transfer patient to hospital urgently. . If meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) suspected, benzylpenicillin sodium p. 577 should be given before transfer to hospital, so long as this does not delay the transfer. If a patient with suspected bacterial meningitis without non-blanching rash cannot be transferred to hospital urgently, benzylpenicillin sodium should be given before the transfer. Cefotaxime p. 555 may be an alternative in penicillin allergy; chloramphenicol p. 601 may be used if history of immediate hypersensitivity reaction to penicillin or to cephalosporins. . In hospital, consider adjunctive treatment with dexamethasone p. 712 (particularly if pneumococcal meningitis suspected in adults), preferably starting before or with first dose of antibacterial, but no later than 12 hours after starting antibacterial; avoid dexamethasone in septic shock, meningococcal septicaemia, or if immunocompromised, or in meningitis following surgery. In hospital, if aetiology unknown: . Adult and child 3 months–50 years, cefotaxime (or ceftriaxone p. 556) ▶Consider adding vancomycin p. 562 if prolonged or multiple use of other antibacterials in the last 3 months, or if travelled, in the last 3 months, to areas outside the UK with highly penicillin- and cephalosporin-resistant pneumococci. ▶Suggested duration of treatment at least 10 days . Adult over 50 years cefotaxime (or ceftriaxone) + amoxicillin p. 579 (or ampicillin p. 581) ▶Consider adding vancomycin if prolonged or multiple use of other antibacterials in the last 3 months, or if travelled, in the last 3 months, to areas outside the UK with highly penicillin- and cephalosporin-resistant pneumococci. ▶Suggested duration of treatment at least 10 days Meningitis caused by meningococci . Benzylpenicillin sodium or cefotaxime (or ceftriaxone) ▶Suggested duration of treatment 7 days. . If history of immediate hypersensitivity reaction to penicillin or to cephalosporins, chloramphenicol ▶Suggested duration of treatment 7 days. Meningitis caused by pneumococci Infection . Cefotaxime (or ceftriaxone) ▶Consider adjunctive treatment with dexamethasone, preferably starting before or with first dose of antibacterial, but no later than 12 hours after starting antibacterial (may reduce penetration of vancomycin into cerebrospinal fluid). ▶If micro-organism penicillin-sensitive, replace cefotaxime with benzylpenicillin sodium. ▶If micro-organism highly penicillin- and cephalosporin- resistant, add vancomycin and if necessary rifampicin p. 615. ▶Suggested duration of antibacterial treatment 14 days Meningitis caused by Haemophilus influenzae . Cefotaxime (or ceftriaxone) ▶Consider adjunctive treatment with dexamethasone, preferably starting before or with first dose of antibacterial, but no later than 12 hours after starting antibacterial. ▶Suggested duration of antibacterial treatment 10 days. ▶For H. influenzae type b give rifampicin for 4 days before hospital discharge to those under 10 years of age or to those in contact with vulnerable household contacts . If history of immediate hypersensitivity reaction to penicillin or to cephalosporins, or if micro-organism resistant to cefotaxime , chloramphenicol ▶Consider adjunctive treatment with dexamethasone, preferably starting before or with first dose of antibacterial, but no later than 12 hours after starting antibacterial. ▶Suggested duration of antibacterial treatment 10 days. ▶For H. influenzae type b give rifampicin for 4 days before hospital discharge to those under 10 years of age or to those in contact with vulnerable household contacts Meningitis caused by Listeria . Amoxicillin (or ampicillin) + gentamicin p. 545 ▶Suggested duration of treatment 21 days. ▶Consider stopping gentamicin after 7 days. . If history of immediate hypersensitivity reaction to penicillin, co-trimoxazole p. 594 ▶Suggested duration of treatment 21 days. Diabetic foot infections, antibacterial therapy Diabetic foot infection Diabetic foot infection is defined as any type of skin, soft tissue or bone infection below the ankle in patients with diabetes. It includes cellulitis, paronychia, abscesses, myositis, tendonitis, necrotising fasciitis, osteomyelitis, and septic arthritis. It is defined clinically by the presence of at least 2 of the following: local swelling or induration, erythema, local tenderness or pain, local warmth, or purulent discharge. For guidance on classification of infection severity, see NICE guideline: Diabetic foot problems (see Useful resources). Treatment g Refer patients immediately to acute services and inform the multidisciplinary foot care service if they have a limb-threatening or life-threatening problem, such as ulceration with fever or any signs of sepsis, ulceration with limb ischaemia, or gangrene. Antibacterial treatment should be started as soon as possible if diabetic foot infection is suspected. Samples (such Infection as soft tissue, bone sample, or deep swab) should be taken for microbiological testing before, or as close as possible to, the start of antibacterial treatment. Offer an antibacterial taking into account the severity of infection, risk of complications, previous microbiological results, recent antibacterial use, and patient preferences. h For other considerations such as switching from intravenous to oral antibacterials, and for advice to be given to patients, see Antibacterials, principles of therapy p. 527. Reassessment g Reassess if symptoms worsen rapidly or significantly at any time, do not start to improve within 1–2 days of starting antibacterial treatment, or the patient becomes systemically very unwell or has severe pain out of proportion to the infection. Take into account other diagnoses (such as pressure sores, gout, or non-infected ulcers), signs and symptoms of a more serious illness (such as limb ischaemia, osteomyelitis, necrotising fasciitis, or sepsis), and previous antibacterial use. Review the choice of antibacterial when microbiological results are available and change according to the results, using a narrower-spectrum antibacterial if appropriate. h Choice of antibacterial therapy g Treatment should be based on clinical assessment, infection severity, suspected micro-organism, and be guided by microbiological results when available. Treatment duration should be based on the severity of infection, and clinical assessment of response to treatment. Review the need for continued antibacterials regularly. Offer oral antibacterials to patients who are able to take oral treatment and the severity of their condition does not require intravenous treatment. h Mild infection . Oral first line : ▶g Flucloxacillin p. 586. ▶Alternative in penicillin allergy or flucloxacillin unsuitable: clarithromycin p. 567, doxycycline p. 597, or erythromycin p. 569 (in pregnancy). h Moderate or severe infection . Treatment duration is based on clinical assessment; minimum of 7 days and up to 6 weeks for osteomyelitis (use oral antibacterials for prolonged treatment). In severe infection, intravenous antibacterials should be given for at least 48 hours (until stabilised). . Oral or Intravenous first line : ▶g Flucloxacillin with or without intravenous gentamicin p. 545 and/or metronidazole p. 572, or co- amoxiclav p. 582 with or without intravenous gentamicin p. 545, or intravenous ceftriaxone p. 556 with metronidazole p. 572. ▶Alternative in penicillin allergy: co-trimoxazole p. 594 [unlicensed] with or without intravenous gentamicin p. 545 and/or metronidazole p. 572. ▶Additional antibacterial choices if Pseudomonas aeruginosa suspected or confirmed: intravenous piperacillin with tazobactam p. 576, or clindamycin p. 564 with ciprofloxacin p. 590 and/or intravenous gentamicin p. 545. ▶If meticillin-resistant Staphylococcus aureus (MRSA) confirmed or suspected add intravenous vancomycin p. 562, or intravenous teicoplanin p. 561, or linezolid p. 605 (specialist use only if vancomycin or teicoplanin cannot be used). ▶Other antibacterials may be appropriate based on microbiological results and specialist advice. h Useful Resources Diabetic foot problems: prevention and management. National Institute for Health and Care Excellence. NICE guideline 19. August 2015, updated October 2019. www.nice.org.uk/guidance/ng19 Ear infections, antibacterial therapy Otitis externa Otitis externa can be triggered by a bacterial infection caused by Pseudomonas aeruginosa or Staphylococcus aureus. Consider systemic antibacterial if spreading cellulitis or patient systemically unwell. Choice of antibacterial therapy No penicillin allergy . Flucloxacillin p. 586 Penicillin allergy or intolerance . Clarithromycin p. 567 (or azithromycin p. 566 or erythromycin p. 569) If pseudomonas suspected . Ciprofloxacin p. 590 (or an aminoglycoside) For topical treatments, see Otitis externa, under Ear p. 1259. Otitis media Acute otitis media is an inflammation in the middle ear associated with effusion and accompanied by an ear infection. Acute otitis media is commonly seen in children and is generally caused by viruses (respiratory syncytial virus and rhinovirus) or bacteria (Haemophilus influenzae, Streptococcus pneumoniae, Streptococcus pyogenes, and Moraxella catarrhalis); both virus and bacteria often co-exist. For further information see Acute otitis media in Ear p. 1259. g Antibacterial therapy should be offered to children with acute otitis media who are systemically very unwell, have signs and symptoms of a more serious illness, or those who are at high-risk of serious complications due to pre- existing comorbidities. Antibacterial therapy should also be considered if otorrhoea (discharge following perforation of the eardrum) is present, or in children under 2 years of age with bilateral otitis media. h Choice of antibacterial therapy in children No penicillin allergy . First line: g amoxicillin p. 579. h . Second line (worsening symptoms despite 2 to 3 days of antibacterial treatment): g co-amoxiclav p. 582. h Penicillin allergy or intolerance . First line: g clarithromycin p. 567 or erythromycin p. 569 (preferred in pregnancy). h . Second line (worsening symptoms despite 2 to 3 days of antibacterial treatment): g Consult local microbiologist. h Eye infections, antibacterial therapy Conjunctivitis (purulent) . Chloramphenicol eye drops p. 1236. Gastro-intestinal system infections, antibacterial therapy Gastro-enteritis Frequently self-limiting and may not be bacterial. . Antibacterial not usually indicated Campylobacter enteritis Frequently self-limiting; treat if immunocompromised or if severe infection. . Clarithromycin p. 567 (or azithromycin p. 566 or erythromycin p. 569) . Alternative, ciprofloxacin p. 590 ▶Strains with decreased sensitivity to ciprofloxacin isolated frequently Diverticulitis, acute Acute diverticulitis is a condition where diverticula (small pouches protruding from the walls of the large intestine) suddenly become inflamed or infected. Complicated acute diverticulitis refers to diverticulitis associated with complications such as abscess, bowel perforation and peritonitis, fistula, intestinal obstruction, haemorrhage, or sepsis. For further information on acute diverticulitis including the non-antibacterial management, see Diverticular disease and diverticulitis p. 40. Treatment g For patients with acute diverticulitis who are systemically well, consider a watchful waiting and a no antibacterial prescribing strategy. Advise patients to re- present if symptoms persist or worsen. For patients who are systemically unwell, immunosuppressed, or have significant comorbidities, an antibacterial prescribing strategy should be offered. Oral antibacterials should be offered to patients who are systemically unwell but do not meet the referral criteria for suspected complicated acute diverticulitis. Patients with persistent or worsening symptoms should be reassessed in primary care and considered for referral to hospital for further assessment. Patients with suspected complicated acute diverticulitis and uncontrolled abdominal pain should be referred for same-day hospital assessment. Patients admitted to hospital with suspected or confirmed complicated acute diverticulitis should be treated with intravenous antibacterials. h For guidance on the management of suspected sepsis, see NICE guideline Sepsis at: www.nice.org.uk/guidance/ng51. For other considerations such as switching from intravenous to oral antibacterials, and for advice to be given to patients, see Antibacterials, principles of therapy p. 527. g Antibacterial prophylaxis is not recommended to prevent recurrent acute diverticulitis. h Choice of antibacterial therapy g Patients unable to take oral treatment should be referred to hospital. h Suspected or confirmed uncomplicated acute diverticulitis . Oral first line : ▶g Co-amoxiclav p. 582. ▶Alternative in penicillin allergy or co-amoxiclav unsuitable: cefalexin p. 551 (caution in penicillin allergy) with metronidazole p. 572, or trimethoprim p. 607 with metronidazole p. 572, or ciprofloxacin p. 590 (only if switching from intravenous route with specialist advice) with metronidazole p. 572. h Suspected or confirmed complicated acute diverticulitis . Intravenous first line : ▶g Co-amoxiclav, or cefuroxime p. 553 with metronidazole p. 572, or amoxicillin p. 579 with gentamicin p. 545 and metronidazole p. 572. ▶Alternative in penicillin and cephalosporins allergy: ciprofloxacin p. 590 with metronidazole p. 572. ▶For alternative antibacterials consult local microbiologist. Infection h Salmonella (non-typhoid) Treat invasive or severe infection. Do not treat less severe infection unless there is a risk of developing invasive infection (e.g. immunocompromised patients, those with haemoglobinopathy, or children under 6 months of age). . Ciprofloxacin or cefotaxime p. 555 Shigellosis Antibacterial not indicated for mild cases. . Ciprofloxacin or azithromycin . Alternatives if micro-organism sensitive, amoxicillin p. 579 or trimethoprim p. 607 Typhoid fever Infections from Middle-East, South Asia, and South-East Asia may be multiple-antibacterial-resistant and sensitivity should be tested. . Cefotaxime (or ceftriaxone p. 556) ▶azithromycin may be an alternative in mild or moderate disease caused by multiple-antibacterial-resistant organisms. . Alternative if micro-organism sensitive, ciprofloxacin Clostridioides difficile infection Clostridioides difficile infection is caused by colonisation of the colon with Clostridioides difficile and production of toxin. It often follows antibiotic therapy and is usually of acute onset, but may become chronic. It is a particular hazard of ampicillin p. 581, amoxicillin, co-amoxiclav, second- and third-generation cephalosporins, clindamycin p. 564, and quinolones, but few antibiotics are free of this side-effect. Treatment options include metronidazole p. 572, vancomycin p. 562, and fidaxomicin p. 603. . For first episode of mild to moderate infection, oral metronidazole ▶Suggested duration of treatment 10–14 days . For second or subsequent episode of infection, for severe infection, for infection not responding to metronidazole , or in patients intolerant of metronidazole, oral vancomycin ▶For severe infection in patients with multiple co- morbidities who are receiving treatment with other antibacterials, or for second or subsequent episode of infection, fidaxomicin can replace vancomycin ▶Suggested duration of treatment 10–14 days . For infection not responding to vancomycin or fidaxomicin , for life-threatening infection, or in patients with ileus, oral vancomycin + i/v metronidazole ▶For infection not responding to vancomycin in patients without life-threatening infection or ileus, fidaxomicin can be used instead of vancomycin + metronidazole ▶Suggested duration of treatment 10–14 days Biliary-tract infection . Ciprofloxacin or gentamicin p. 545 or a cephalosporin Peritonitis . A cephalosporin + metronidazole or gentamicin + metronidazole or gentamicin + clindamycin or piperacillin with tazobactam p. 576 alone Peritonitis: peritoneal dialysis-associated . Vancomycin (or teicoplanin p. 561) + ceftazidime p. 555 added to dialysis fluid or vancomycin added to dialysis fluid + ciprofloxacin by mouth ▶Suggested duration of treatment 14 days or longer Infection Genital system infections, antibacterial therapy Bacterial vaginosis . Oral metronidazole p. 572 ▶Suggested duration of treatment 5–7 days (or high-dose metronidazole as a single dose) . Alternatively, topical metronidazole for 5 days or topical clindamycin p. 874 for 7 days Uncomplicated genital chlamydial infection, non- gonococcal urethritis, and non-specific genital infection Contact tracing recommended. . Azithromycin p. 566 or doxycycline p. 597 ▶Suggested duration of treatment azithromycin as a single dose or doxycycline for 7 days . Alternatively, erythromycin p. 569. ▶Suggested duration of treatment 14 days Gonorrhoea: uncomplicated Contact tracing recommended. Consider chlamydia co- infection. Choice of alternative antibacterial regimen depends on locality where infection acquired. . Azithromycin + i/m ceftriaxone p. 556 ▶Suggested duration of treatment is a single-dose of each antibacterial . Alternatively, when parenteral administration is not possible, cefixime p. 555 + azithromycin ▶Suggested duration of treatment is a single-dose of each antibacterial . Alternatively, if micro-organism is sensitive to a quinolone, ciprofloxacin p. 590 + azithromycin ▶Suggested duration of treatment is a single-dose of each antibacterial . Pharyngeal infection, azithromycin + i/m ceftriaxone ▶Suggested duration of treatment is a single-dose of each antibacterial Pelvic inflammatory disease Contact tracing recommended. . Doxycycline + metronidazole + single-dose of i/m ceftriaxone or ofloxacin p. 593 + metronidazole ▶Suggested duration of treatment 14 days (except i/m ceftriaxone). ▶In severely ill patients initial treatment with doxycycline + i/v ceftriaxone + i/v metronidazole, then switch to oral treatment with doxycycline + metronidazole to complete 14 days’ treatment Early syphilis (infection of less than 2 years) Contact tracing recommended. . Benzathine benzylpenicillin p. 577 ▶Suggested duration of treatment single-dose (repeat dose after 7 days for women in the third trimester of pregnancy) . Alternatively, doxycycline or erythromycin ▶Suggested duration of treatment 14 days Late latent syphilis (asymptomatic infection of more than 2 years) Contact tracing recommended. . Benzathine benzylpenicillin ▶Suggested duration of treatment once weekly for 2 weeks . Alternatively, doxycycline ▶Suggested duration of treatment 28 days Asymptomatic contacts of patients with infectious syphilis . Doxycycline ▶Suggested duration of treatment 14 days Musculoskeletal system infections, antibacterial therapy Osteomyelitis For management of osteomyelitis below the ankle in individuals with diabetes mellitus, see Diabetic foot infections, antibacterial therapy p. 533. Seek specialist advice if chronic infection or prostheses present. . Flucloxacillin p. 586 ▶Consider adding fusidic acid p. 604 or rifampicin p. 615 for initial 2 weeks. ▶Suggested duration of treatment 6 weeks for acute infection . If penicillin-allergic, clindamycin p. 564 ▶Consider adding fusidic acid or rifampicin for initial 2 weeks. ▶Suggested duration of treatment 6 weeks for acute infection . If meticillin-resistant Staphylococcus aureus suspected, vancomycin p. 562 (or teicoplanin p. 561) ▶Consider adding fusidic acid or rifampicin for initial 2 weeks. ▶Suggested duration of treatment 6 weeks for acute infection Septic arthritis For management of septic arthritis below the ankle in individuals with diabetes mellitus, see Diabetic foot infections, antibacterial therapy p. 533. Seek specialist advice if prostheses present. . Flucloxacillin ▶Suggested duration of treatment 4–6 weeks (longer if infection complicated). . If penicillin-allergic, clindamycin ▶Suggested duration of treatment 4–6 weeks (longer if infection complicated). . If meticillin-resistant Staphylococcus aureus suspected, vancomycin (or teicoplanin) ▶Suggested duration of treatment 4–6 weeks (longer if infection complicated). . If gonococcal arthritis or Gram-negative infection suspected, cefotaxime p. 555 (or ceftriaxone p. 556) ▶Suggested duration of treatment 4–6 weeks (longer if infection complicated; treat gonococcal infection for 2 weeks). Nose infections, antibacterial therapy Sinusitis (acute) Acute sinusitis is generally triggered by a viral infection, although occasionally it may become complicated by a bacterial infection caused by Streptococcus pneumoniae, Haemophylus influenzae, Moraxella catharrhalis, or Staphylococcus aureus. For further information see Sinusitis (acute) p. 1268. Treatment g Antibacterial therapy should only be offered to patients with acute sinusitis who are systemically very unwell, have signs and symptoms of a more serious illness, those who are at high-risk of complications due to pre-existing comorbidities, or whenever bacterial sinusitis is suspected. Patients presenting with symptoms for around 10 days or more with no improvement may be prescribed a back-up antibiotic prescription, which can be used if symptoms do not improve within 7 days or if they worsen significantly at any time. h For further information see, Sinusitis (acute) p. 1268. Choice of antibacterial therapy No penicillin allergy . First line: ▶g Non-life threatening symptoms: phenoxymethylpenicillin p. 578. ▶Systemically very unwell, signs and symptoms of a more serious illness, or at high-risk of complications: co- amoxiclav p. 582. h . Second line (worsening symptoms despite 2 or 3 days of antibiotic treatment): ▶g Non-life threatening symptoms: co-amoxiclav. ▶Systemically very unwell, signs and symptoms of a more serious illness or at high-risk of complications: consult local microbiologist. h Penicillin allergy or intolerance . First line: g doxycycline p. 597 or clarithromycin p. 567 (erythromycin p. 569 in pregnancy). h . Second line (worsening symptoms despite 2 or 3 days of antibiotic treatment): g Consult local microbiologist. h Useful Resources Sinusitis (acute): antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 79. October 2017. www.nice.org.uk/guidance/ng79 Oral bacterial infections Antibacterial drugs Antibacterial drugs should only be prescribed for the treatment of oral infections on the basis of defined need. They may be used in conjunction with (but not as an alternative to) other appropriate measures, such as providing drainage or extracting a tooth. The ‘blind’ prescribing of an antibacterial for unexplained pyrexia, cervical lymphadenopathy, or facial swelling can lead to difficulty in establishing the diagnosis. In severe oral infections, a sample should always be taken for bacteriology. Oral infections which may require antibacterial treatment include acute periapical or periodontal abscess, cellulitis, acutely created oral-antral communication (and acute sinusitis), severe pericoronitis, localised osteitis, acute necrotising ulcerative gingivitis, and destructive forms of chronic periodontal disease. Most of these infections are readily resolved by the early establishment of drainage and removal of the cause (typically an infected necrotic pulp). Antibacterials may be required if treatment has to be delayed, in immunocompromised patients, or in those with conditions such as diabetes or Paget’s disease. Certain rarer infections including bacterial sialadenitis, osteomyelitis, actinomycosis, and infections involving fascial spaces such as Ludwig’s angina, require antibiotics and specialist hospital care. Antibacterial drugs may also be useful after dental surgery in some cases of spreading infection. Infection may spread to involve local lymph nodes, to fascial spaces (where it can cause airway obstruction), or into the bloodstream (where it can lead to cavernous sinus thrombosis and other serious complications). Extension of an infection can also lead to maxillary sinusitis; osteomyelitis is a complication, which usually arises when host resistance is reduced. If the oral infection fails to respond to antibacterial treatment within 48 hours the antibacterial should be changed, preferably on the basis of bacteriological investigation. Failure to respond may also suggest an incorrect diagnosis, lack of essential additional measures (such as drainage), poor host resistance, or poor patient Infection compliance. Combination of a penicillin (or a macrolide) with metronidazole p. 572 may sometimes be helpful for the treatment of severe oral infections or oral infections that have not responded to initial antibacterial treatment. Penicillins Phenoxymethylpenicillin p. 578 is effective for dentoalveolar abscess. Broad-spectrum penicillins . Amoxicillin p. 579 is as effective as phenoxymethylpenicillin but is better absorbed; however, it may encourage emergence of resistant organisms. Like phenoxymethylpenicillin, amoxicillin is ineffective against bacteria that produce beta-lactamases. Amoxicillin may be useful for short course oral regimens. Co-amoxiclav p. 582 is active against beta-lactamase- producing bacteria that are resistant to amoxicillin. Co- amoxiclav may be used for severe dental infection with spreading cellulitis or dental infection not responding to first-line antibacterial treatment. Cephalosporins The cephalosporins offer little advantage over the penicillins in dental infections, often being less active against anaerobes. Infections due to oral streptococci (often termed viridans streptococci) which become resistant to penicillin are usually also resistant to cephalosporins. This is of importance in the case of patients who have had rheumatic fever and are on long-term penicillin therapy. Cefalexin p. 551 and cefradine p. 552 have been used in the treatment of oral infections. Tetracyclines In adults, tetracyclines can be effective against oral anaerobes but the development of resistance (especially by oral streptococci) has reduced their usefulness for the treatment of acute oral infections; they may still have a role in the treatment of destructive (refractory) forms of periodontal disease. Doxycycline p. 597 has a longer duration of action than tetracycline p. 600 or oxytetracycline p. 600 and need only be given once daily; it is reported to be more active against anaerobes than some other tetracyclines. Doxycycline may have a role in the treatment of recurrent aphthous ulceration, or as an adjunct to gingival scaling and root planing for periodontitis. Macrolides The macrolides are an alternative for oral infections in penicillin-allergic patients or where a beta-lactamase producing organism is involved. However, many organisms are now resistant to macrolides or rapidly develop resistance; their use should therefore be limited to short courses. Clindamycin Clindamycin p. 564 should not be used routinely for the treatment of oral infections because it may be no more effective than penicillins against anaerobes and there may be cross-resistance with erythromycin-resistant bacteria p. 569. Clindamycin can be used for the treatment of dentoalveolar abscess that has not responded to penicillin or to metronidazole. Metronidazole and tinidazole Metronidazole is an alternative to a penicillin for the treatment of many oral infections where the patient is allergic to penicillin or the infection is due to beta- lactamase-producing anaerobes. It is the drug of first choice for the treatment of acute necrotising ulcerative gingivitis (Vincent’s infection) and pericoronitis; amoxicillin is a suitable alternative. For these purposes metronidazole for Infection 3 days is sufficient, but the duration of treatment may need to be longer in pericoronitis. Tinidazole p. 574 is licensed for the treatment of acute ulcerative gingivitis. Respiratory system infections, antibacterial therapy Epiglottitis (Haemophilus influenzae) . Cefotaxime p. 555 (or ceftriaxone p. 556) . If history of immediate hypersensitivity reaction to penicillin or to cephalosporins, chloramphenicol p. 601 Bronchiectasis (non-cystic fibrosis), acute exacerbation Bronchiectasis is a persistent or progressive condition, caused by chronic inflammatory damage to the airways and is characterised by thick-walled, dilated bronchi. Signs and symptoms may range from intermittent expectoration and infection, to chronic cough, persistent daily production of sputum, bacterial colonisation, and recurrent infections. An acute exacerbation is defined as sustained deterioration of the patient’s signs and symptoms from their baseline, and presents with worsening local symptoms, with or without increased wheeze, breathlessness or haemoptysis and may be accompanied by fever or pleurisy. Treatment g Obtain a sputum sample and send for culture and susceptibility testing. Antibacterial therapy should be given to all patients with an acute exacerbation. h For patients receiving prophylactic antibacterial therapy, switching from intravenous to oral antibacterials, and for advice to be given to patients, see Antibacterials, principles of therapy p. 527. g Refer patients to hospital if they have signs or symptoms suggestive of a more serious illness such as cardiorespiratory failure or sepsis. h Reassessment g Reassess if symptoms worsen rapidly or significantly at any time and consider: . Other diagnoses such as pneumonia, or signs and symptoms of a more serious illness such as cardiorespiratory failure, or sepsis; . Previous antibacterial use that may have led to resistance. Review choice of antibacterial if susceptibility results indicate bacterial resistance and symptoms are not improving—consult local microbiologist as needed. h Choice of antibacterial therapy g The recommended total duration of treatment is 7–14 days. Treatment should be guided by the most recent sputum culture and susceptibility results when available. Seek specialist advice for patients whose symptoms are not improving with repeated courses, or who are resistant to, or cannot take oral antibacterials. h . Oral first line : ▶g Amoxicillin p. 579, clarithromycin p. 567, or doxycycline p. 597. ▶Alternative if at high risk of treatment failure (repeated courses of antibacterials, previous culture with resistant or atypical bacteria, or high risk of complications): co- amoxiclav p. 582, or levofloxacin p. 592. h ▶Intravenous first line (severely unwell or unable to take oral treatment): ▶g Co-amoxiclav, piperacillin with tazobactam p. 576, or levofloxacin. h Antibacterial prophylaxis . g For patients with repeated acute exacerbations, a trial of antibacterial prophylaxis may be given on specialist advice only. h Chronic obstructive pulmonary disease, acute exacerbation An acute exacerbation of chronic obstructive pulmonary disease (COPD) is a sustained worsening of symptoms from the patient’s usual stable state, that is beyond the usual day to day variations. Many exacerbations are not caused by bacterial infections, but instead can be triggered by other factors such as smoking or viral infections. For the non-antibacterial management of acute exacerbations of COPD, see Chronic obstructive pulmonary disease p. 256. Treatment g Consider antibacterial treatment taking into account: . The severity of symptoms, sputum colour changes and increases in volume and thickness; . The need for hospital admission; . Previous exacerbations and hospital admission history, and risk of developing complications. h For other considerations such as in patients receiving prophylactic antibacterial therapy, switching from intravenous to oral antibacterials, and for advice to be given to patients, see Antibacterials, principles of therapy p. 527. g Refer patients to hospital if they have signs or symptoms suggestive of a more serious illness such as cardiorespiratory failure or sepsis. h Reassessment g Reassess if symptoms worsen rapidly or significantly at any time and consider: . Other diagnoses such as pneumonia, or signs and symptoms of a more serious illness such as cardiorespiratory failure, or sepsis; . Previous antibacterial use that may have led to resistance. Send a sputum sample for testing if there is no improvement after antibacterial therapy and this has not already been done. Review choice of antibacterial if susceptibility results indicate bacterial resistance and symptoms are not improving—consult local microbiologist as needed. h Choice of antibacterial therapy g The recommended total duration of treatment is 5 days. Treatment should be guided by the most recent sputum culture and susceptibility results when available. Seek specialist advice for patients whose symptoms are not improving with repeated courses, or who are resistant to, or cannot take oral antibacterials. h . Oral first line : ▶g Amoxicillin, clarithromycin, or doxycycline. ▶Alternative if at high risk of treatment failure (repeated courses of antibacterials, previous culture with resistant or atypical bacteria, or high risk of complications): co- amoxiclav, or levofloxacin. h . Oral second line (if no improvement after at least 2 to 3 days): ▶g Use a first line antibacterial from a different class to the antibacterial used previously. ▶Alternative if at high risk of treatment failure: co- amoxiclav, levofloxacin, or co-trimoxazole p. 594 (only when sensitivities are available and there is good reason to use co-trimoxazole over single antibacterials). h . Intravenous first line (severely unwell or unable to take oral treatment): ▶g Amoxicillin, co-amoxiclav, clarithromycin, co- trimoxazole, or piperacillin with tazobactam. h . Intravenous second line : g Choice should be made in consultation with a local microbiologist. h Cough, acute Acute cough is usually self-limiting and often resolves within 3–4 weeks without antibacterials. It is most commonly caused by a viral upper respiratory tract infection, but can have other infective causes such as acute bronchitis or pneumonia, or non-infective causes such as interstitial lung disease or gastro-oesophageal reflux disease. Treatment g Patients should be advised that an acute cough is usually self-limiting and to manage their symptoms using self-care treatments. These include honey and over-the- counter cough medicines containing expectorants or cough suppressants, however there is limited evidence to support the use of such products. For more information, see Aromatic inhalations, cough preparations and systemic nasal decongestants p. 311. Patients with an acute cough who are systemically very unwell should be offered immediate antibacterial treatment. Do not routinely offer an antibacterial to treat an acute cough associated with an upper respiratory tract infection or acute bronchitis in patients who are not systemically very unwell or at higher risk of complications. h Patients with a pre-existing co-morbidity, young children who were born prematurely, and patients aged over 65 years of age and the presence of certain criteria (hospitalisation in the previous year, type 1 or 2 diabetes, history of congestive heart failure, or currently taking oral corticosteroids) are considered to be at a higher risk of complications if they present with an acute cough. g Immediate or back-up antibacterial treatment should be considered in these patients based on the face-to-face clinical examination. If back-up treatment is given, advise patients to start treatment if symptoms worsen rapidly or significantly at any time. h For general advice to give to patients, see Antibacterials, principles of therapy p. 527. g Seek specialist advice, or refer patients with an acute cough to hospital if they have signs or symptoms of a more serious illness or condition. h Reassessment g Reassess if symptoms worsen rapidly or significantly taking into account alternative diagnoses, signs or symptoms suggestive of a more serious condition, and previous antibacterial use which may have led to resistant bacteria. h Choice of antibacterial therapy g The recommended duration of oral treatment is 5 days. h . First line ▶g Doxycycline p. 597. ▶Alternative first line choices: amoxicillin p. 579, clarithromycin p. 567, or erythromycin p. 569. h . Choice during pregnancy: ▶g Amoxicillin or erythromycin. h Pneumonia, community-acquired Pneumonia is an acute infection of the lung parenchyma that presents with symptoms such as cough, chest pain, dyspnoea, and fever. It is classified as community-acquired if acquired outside of hospital or in a nursing home. For recommendations on the management of pneumonia during the COVID-19 pandemic, see NICE rapid guidelines: Managing suspected or confirmed pneumonia in adults in the community (available at: www.nice.org.uk/guidance/ ng165), and Antibiotics for pneumonia in adults in hospital for patients presenting to hospital with community acquired pneumonia (available at: www.nice.org.uk/guidance/ng173). Where the new recommendations cover existing recommendations discussed below, follow the rapid guideline recommendations during the pandemic. For further information on COVID-19, see COVID-19 p. 656. Treatment Infection g Offer an antibacterial taking into account the severity assessment, risk of complications, local antimicrobial resistance and surveillance data, recent antibacterial use, and recent microbiological results. h For severity assessment and guidance on monitoring, see NICE guideline on pneumonia in adults (see Useful resources). g Antibacterial treatment should be started as soon as possible and within 4 hours of establishing a diagnosis (within 1 hour if the patient has suspected sepsis and meets any of the high risk criteria for this — see NICE guideline on sepsis at: www.nice.org.uk/guidance/ng51). Refer patients to hospital as recommended in the NICE guideline on pneumonia in adults, or if they have signs or symptoms suggestive of a more serious illness (such as cardiorespiratory failure or sepsis). In patients with moderate or high-severity community- acquired pneumonia, obtain blood and sputum cultures and consider performing pneumococcal and legionella urinary antigen tests. Do not routinely offer a glucocorticoid to patients with community-acquired pneumonia unless they have other conditions for which glucocorticoid treatment is indicated. h For other considerations such as switching from intravenous to oral antibacterials, and for advice to be given to patients, see Antibacterials, principles of therapy p. 527. Reassessment g Reassess if signs or symptoms do not improve or worsen rapidly or significantly, and consider other possible non-bacterial causes such as influenza. If a sample has been sent for microbiological testing, review the choice of antibacterial and consider changing according to the results, using a narrower-spectrum antibacterial if appropriate. Send a sample (such as sputum sample) for testing if there is no improvement after antibacterial therapy and this has not already been done. Refer patients to hospital if symptoms do not improve as expected with antibacterial treatment. h Choice of antibacterial therapy g Treatment should be based on severity assessment using clinical judgement and CRB65 or CURB65, suspected micro-organism, and in moderate and high-severity community-acquired pneumonia microbiological results when available. Offer oral antibacterials to patients who are able to take oral treatment and the severity of their condition does not require intravenous treatment. Consider referral to hospital or seeking specialist advice if bacteria are resistant to oral antibacterials or patients cannot take oral treatment. h Low severity . Oral first line : ▶g Amoxicillin. ▶Alternative in penicillin allergy or amoxicillin unsuitable (e.g. atypical pathogens suspected): clarithromycin, doxycycline, or erythromycin (in pregnancy). h Moderate severity . Oral first line : ▶g Amoxicillin. ▶If atypical pathogens suspected: amoxicillin with clarithromycin or erythromycin (in pregnancy). ▶Alternative in penicillin allergy: clarithromycin, or doxycycline. h High severity . Oral or Intravenous first line : ▶g Co-amoxiclav p. 582 with clarithromycin or oral erythromycin (in pregnancy). ▶Alternative in penicillin allergy: levofloxacin p. 592 (consult local microbiologist if fluoroquinolone not Infection appropriate). h Pneumonia, hospital-acquired Pneumonia is an acute infection of the lung parenchyma that presents with symptoms such as cough, chest pain, dyspnoea, and fever. It is classified as hospital-acquired when it develops 48 hours or more after hospital admission. For recommendations on the management of suspected or confirmed pneumonia during the COVID-19 pandemic, see NICE rapid guideline: Antibiotics for pneumonia in adults in hospital (available at: www.nice.org.uk/guidance/ng173). Where the new recommendations cover existing recommendations discussed below, follow the rapid guideline recommendations during the pandemic. For further information on COVID-19, see COVID-19 p. 656. Treatment g In patients with signs or symptoms of pneumonia starting within 48 hours of hospital admission, follow recommendations for patients with community-acquired pneumonia. Offer an antibacterial taking into account: . The severity of signs or symptoms; . The number of days in hospital before onset of symptoms; . The risk of complications; . Local hospital and ward-based antimicrobial resistance data; . Recent antibacterial use; . Recent microbiological test results; . Recent contact with health or social care settings; . Risk of adverse effects such as Clostridioides difficile infection. Antibacterial treatment should be started as soon as possible and within 4 hours of establishing a diagnosis (within 1 hour if the patient has suspected sepsis and meets any of the high risk criteria for this — see NICE guideline on sepsis at: www.nice.org.uk/guidance/ng51). A sample (for example, sputum sample, nasopharyngeal swab, or tracheal aspirate) should be taken for microbiological testing. h For other considerations such as switching from intravenous to oral antibacterials, and for advice to be given to patients, see Antibacterials, principles of therapy p. 527. Reassessment g Reassess if symptoms do not improve or worsen rapidly or significantly. When microbiological results are available, review choice of antibacterial and change treatment according to the results, using a narrower-spectrum antibacterial if appropriate. Seek advice from a microbiologist if symptoms do not improve as expected with treatment, or multidrug-resistant bacteria are present. h Choice of antibacterial therapy g For patients with non-severe signs or symptoms and not at higher risk of resistance, treatment should be guided by microbiological results when available. For patients with severe signs or symptoms or at higher risk of resistance, treatment should be based on specialist microbiological advice and local resistance data. Higher risk of resistance includes signs or symptoms starting more than 5 days after hospital admission, relevant comorbidity, recent use of broad-spectrum antibacterials, colonisation with multidrug-resistant bacteria, and recent contact with a health or social care setting before the current admission. In patients with signs or symptoms of pneumonia starting within 3 to 5 days of hospital admission who are not at higher risk of resistance, consider following the recommendations for community-acquired pneumonia for choice of antibacterial treatment. h Non-severe signs or symptoms and not at higher risk of resistance . Oral first line : ▶g Co-amoxiclav p. 582. ▶Alternative in penicillin allergy or co-amoxiclav unsuitable (based on specialist microbiological advice and local resistance data): doxycycline p. 597, cefalexin p. 551 (caution in penicillin allergy), co-trimoxazole p. 594 [unlicensed], or levofloxacin p. 592 [unlicensed] (only if switching from intravenous levofloxacin under specialist advice). h Severe signs or symptoms or at higher risk of resistance . Intravenous first line : ▶g Piperacillin with tazobactam p. 576, ceftazidime p. 555, ceftazidime with avibactam p. 558, ceftriaxone p. 556, cefuroxime p. 553, levofloxacin [unlicensed], or meropenem p. 549. ▶If meticillin-resistant Staphylococcus aureus confirmed or suspected add vancomycin p. 562, or teicoplanin p. 561, or linezolid p. 605 (under specialist advice only if vancomycin cannot be used). h Useful resources Bronchiectasis (non-cystic fibrosis), acute exacerbation: antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 117. December 2018. www.nice.org.uk/guidance/ng117 Chronic obstructive pulmonary disease (acute exacerbation): antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 114. December 2018. www.nice.org.uk/guidance/ng114 Cough (acute): antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 120. February 2019. www.nice.org.uk/guidance/ng120 Pneumonia in adults: diagnosis and management. National Institute for Health and Care Excellence. Clinical guideline 191. December 2014, updated September 2019. www.nice.org.uk/guidance/cg191 Pneumonia (community-acquired): antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 138. September 2019. www.nice.org.uk/guidance/ng138 Pneumonia (hospital-acquired): antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 139. September 2019. www.nice.org.uk/guidance/ng139 Skin infections, antibacterial therapy Impetigo Impetigo is a contagious, superficial bacterial infection of the skin that affects all age groups, but it is more common in young children. Transmission occurs directly through close contact with an infected individual or indirectly via contaminated objects such as toys, clothing, or towels. Impetigo can develop as a primary infection or as a secondary complication of pre-existing skin conditions such as eczema, scabies, or chickenpox. The two main clinical forms are non-bullous impetigo (most common form) and bullous impetigo. Non-bullous impetigo is characterised by thin-walled vesicles or pustules that rupture quickly, forming a golden-brown crust, while bullous impetigo is characterised by the presence of fluid-filled vesicles and blisters that rupture, leaving a thin, flat, yellow-brown crust. Initial treatment g Patients, and if appropriate their family or carers, should be advised on good hygiene measures to reduce the spread of impetigo to other body areas and to other people. In patients with localised non-bullous impetigo who are not systemically unwell or at high risk of complications, consider hydrogen peroxide 1% cream p. 1345; if unsuitable (e.g. if impetigo is around the eyes), offer a topical antibacterial. In patients with widespread non-bullous impetigo who are not systemically unwell or at high risk of complications, offer a topical or oral antibacterial. Take into account that both routes of administration are effective; any previous use of topical antibacterials that could have led to resistance; and the preferences of the patient and, their family or carers (if appropriate), including the practicalities of administration (particularly to large areas). In patients with non-bullous impetigo who are systemically unwell or at high risk of complications and in all patients with bullous impetigo, offer an oral antibacterial. Combination treatment with a topical and oral antibacterial is not recommended. h For other considerations such as advice to be given to patients, and if appropriate their family or carers, see Antibacterials, principles of therapy p. 527. g Refer patients to hospital if they have any signs or symptoms suggestive of a more serious condition or illness, or if they have widespread impetigo and are immunocompromised. Consider referral to hospital or seeking specialist advice for patients who are systemically unwell, have a higher risk of complications, or if impetigo is difficult to treat (such as bullous impetigo (particularly in children aged under 1 year) or frequently recurrent impetigo). h Reassessment and further treatment g Reassess if symptoms worsen rapidly or significantly at any time, or do not improve after completion of the treatment course. Take into consideration other possible diagnoses (such as herpes simplex infection), signs or symptoms suggesting a more serious illness or condition (such as cellulitis), and previous antibacterial use that might have led to resistance. For patients whose impetigo is worsening or has not improved after treatment with hydrogen peroxide 1% cream, offer a topical antibacterial if the infection remains localised, or a topical or oral antibacterial if infection has become widespread. Offer an oral antibacterial to patients whose impetigo is worsening or has not improved after completing a course of topical antibacterial. For patients whose impetigo is worsening or has not improved after completing a course of topical or oral antibacterials, consider sending a skin swab for microbiological testing. For patients with impetigo that recurs frequently, send a skin swab for microbiological testing and consider taking a nasal swab and starting treatment for decolonisation (using topical treatments and personal hygiene measures). If a skin swab has been sent for microbiological testing, review the choice of antibacterial and change according to the results if symptoms are not improving, using a narrower- spectrum antibacterial if possible. h Choice of antibacterial therapy g Treatment should be based on infection severity and number of lesions, suspected micro-organism, local antibacterial resistance data, and be guided by microbiological results if available. h . Topical first line if hydrogen peroxide unsuitable or ineffective: ▶g fusidic acid p. 604. ▶Alternative if fusidic acid resistance suspected or confirmed: mupirocin p. 1297. h . Oral first line : ▶g Flucloxacillin p. 586. ▶Alternative if penicillin allergy or flucloxacillin unsuitable: clarithromycin p. 567 or erythromycin p. 569 (in Infection pregnancy). h . If meticillin-resistant Staphylococcus aureus (MRSA) infection suspected or confirmed: g Consult local microbiologist. h Cellulitis and erysipelas Cellulitis and erysipelas are infections of the subcutaneous tissues, which usually result from contamination of a break in the skin. Both conditions are characterised by acute localised inflammation and oedema. Lesions are more superficial in erysipelas and have a well-defined, raised margin. For management of an infected leg ulcer, see Leg Ulcer, and for infection below the ankle in patients with diabetes, see Diabetic foot infections, antibacterial therapy p. 533. Treatment g Consider taking a swab for microbiological testing only if the skin is broken and there is risk of infection by an uncommon pathogen (for example, after a penetrating injury, exposure to water-born organisms, or an infection acquired outside the UK). Drawing around the extent of the infection to monitor progress before initiating antibacterial treatment can also be considered, taking into account that redness may be less visible on darker skin tones. Offer an antibacterial taking into account the severity of symptoms, site of infection, risk of uncommon pathogens, previous microbiological results from a swab, and the patient’s meticillin-resistant Staphylococcus aureus (MRSA) status if known. h For other considerations such as in patients receiving prophylactic antibacterial therapy, switching from intravenous to oral antibacterials, and for advice to be given to patients, see Antibacterials, principles of therapy p. 527. g Manage any underlying condition that may predispose to cellulitis or erysipelas, such as diabetes mellitus, venous insufficiency, eczema, and oedema. Refer patients to hospital if they have signs or symptoms suggestive of a more serious illness, such as orbital cellulitis, osteomyelitis, septic arthritis, necrotising fasciitis, or sepsis. Consider referral to hospital or seeking specialist advice for patients who have lymphangitis, are severely unwell, are unable to take oral antibacterials, have infection near the eyes or nose, or that could be caused by an uncommon pathogen. h Reassessment g Reassess if symptoms worsen rapidly or significantly at any time, do not improve within 2–3 days of starting an antibacterial, or the patient becomes systemically very unwell, has severe pain out of proportion to the infection, or has redness or swelling spreading beyond the initial presentation (taking into account that some initial spreading may occur). Take into consideration other possible diagnoses (such as an inflammatory reaction to an insect bite or deep vein thrombosis), any underlying condition that may predispose to cellulitis or erysipelas, signs or symptoms suggesting a more serious illness, results from microbiological tests, and previous antibacterial use that might have led to resistance. Consider taking a swab for testing if the skin is broken and this has not already been done. If a swab has been sent for microbiological testing, review the choice of antibacterial and change according to the results if signs or symptoms are not improving, using a narrower-spectrum antibacterial if possible. Consider referral to hospital or seeking specialist advice if the infection has spread and is not responding to oral antibacterials. h Choice of antibacterial therapy g Treatment should be based on clinical assessment, infection severity, suspected micro-organism, and site of Infection infection. Offer oral antibacterials to patients who are able to take oral treatment and the severity of their condition does not require intravenous treatment. Consider referral to hospital or seeking specialist advice if bacteria are resistant to oral antibacterials, patients cannot take oral treatment, or have infection near the eyes or nose. h First choice antibacterials . Oral or Intravenous first line : ▶g Flucloxacillin p. 586. ▶Alternative in penicillin allergy or flucloxacillin unsuitable: clarithromycin p. 567, oral erythromycin p. 569 (in pregnancy), or oral doxycycline p. 597. h . Oral or Intravenous first line if infection near the eyes or nose : ▶g Co-amoxiclav p. 582. ▶Alternative in penicillin allergy or co-amoxiclav unsuitable: clarithromycin with metronidazole p. 572. h Alternative choice antibacterials for severe infection . Oral or Intravenous: ▶g Co-amoxiclav, clindamycin p. 564, intravenous cefuroxime p. 553, or intravenous ceftriaxone p. 556 (ambulatory care only). ▶If meticillin-resistant Staphylococcus aureus confirmed or suspected, add intravenous vancomycin p. 562, intravenous teicoplanin p. 561, or linezolid p. 605 (specialist use only if vancomycin or teicoplanin cannot be used). ▶For ambulatory care, and in MRSA confirmed or suspected infections, other antibacterials may be appropriate based on microbiological results and specialist advice. h Antibacterial prophylaxis g For patients who have been treated in hospital, or under specialist advice, for at least 2 separate episodes of cellulitis or erysipelas in the previous 12 months, a trial of antibacterial prophylaxis may be considered by a specialist. If cellulitis or erysipelas recurs, stop or change the prophylactic antibacterial to an alternative once the acute infection has been treated. Review antibacterial prophylaxis at least every 6 months, assessing the success of therapy and discussing continuing, stopping or changing prophylaxis taking into account the patient’s preference for antibacterial use and the risk of antibacterial resistance. h Leg Ulcer Leg ulcers usually develop on the lower leg, between the shin and the ankle, and take more than 4–6 weeks to heal. Although the majority of leg ulcers may be colonised with bacteria, this does not necessarily mean that the wound is infected. Signs and symptoms of an infected leg ulcer include redness (may be less visible on darker skin tones) or swelling spreading beyond the ulcer, localised warmth, increased pain, or fever. Treatment g Any underlying condition that may cause a leg ulcer, such as venous insufficiency and oedema should be managed to promote healing. Taking a sample for microbiological testing at initial presentation with a leg ulcer is not recommended, even if the ulcer may be infected. Offer an antibacterial to patients who have signs or symptoms of infection taking into account the severity of signs or symptoms, risk of developing complications, and previous antibacterial use. h For other considerations such as switching from intravenous to oral antibacterials and for advice to be given to patients, see Antibacterials, principles of therapy p. 527. g Refer patients to hospital if they have signs or symptoms suggestive of a more serious condition or illness, such as sepsis, necrotising fasciitis, or osteomyelitis. Consider referral to hospital or seeking specialist advice for patients with an infected leg ulcer who have lymphangitis or a higher risk of complications due to comorbidities, such as diabetes or immunosuppression. h Reassessment g Reassess if signs or symptoms worsen rapidly or significantly at any time, do not improve within 2–3 days, or the patient becomes systemically unwell or has severe pain out of proportion to the infection. Take into consideration previous antibacterial use that might have led to resistance, and be aware that full resolution of an infected leg ulcer is not expected until after the antibacterial course is completed. Consider taking a sample from the leg ulcer (after cleaning) for microbiological testing if signs or symptoms of infection are worsening or have not improved as expected. Review the choice of antibacterial(s) and change according to the results if signs or symptoms are not improving, using a narrower-spectrum antibacterial if possible. Consider referral to hospital or seeking specialist advice if patients have a spreading infection that is not responding to oral antibacterials. h Choice of antibacterial therapy g Treatment should be based on clinical assessment, infection severity, suspected micro-organism, and be guided by microbiological results if available. Offer oral antibacterials to patients who are able to take oral treatment and the severity of their condition does not require intravenous treatment. For patients unable to take oral treatment, consider referring or seeking specialist advice and where appropriate, explore options for administration of intravenous or intramuscular antibiotics at home or in the community. h Non-severely unwell patients . Oral first line : ▶g Flucloxacillin. ▶Alternative in penicillin allergy or flucloxacillin unsuitable: doxycycline, clarithromycin, or erythromycin (in pregnancy). h . Oral second line (guided by microbiological results when available): ▶g Co-amoxiclav. ▶Alternative in penicillin allergy: co-trimoxazole p. 594 [unlicensed]. h Severely unwell patients . Oral or Intravenous first line (guided by microbiological results if available): ▶g Intravenous flucloxacillin with or without intravenous gentamicin p. 545 and/or metronidazole, or intravenous co-amoxiclav with or without intravenous gentamicin. ▶Alternative in penicillin allergy: intravenous co- trimoxazole [unlicensed] with or without intravenous gentamicin and/or metronidazole. h . Oral or Intravenous second line (guided by microbiological results when available or following specialist advice): ▶g Intravenous piperacillin with tazobactam p. 576, or intravenous ceftriaxone with or without metronidazole. h Antibacterials to be added if meticillin-resistant Staphylococcus aureus (MRSA) infection suspected or confirmed . Oral or Intravenous(in addition to antibacterials listed above): ▶g Intravenous vancomycin, intravenous teicoplanin, or linezolid (specialist use only if vancomycin or teicoplanin cannot be used). h Animal and human bites Cleanse wound thoroughly. For tetanus-prone wound, give human tetanus immunoglobulin p. 1360 (with a tetanus- containing vaccine if necessary, according to immunisation history and risk of infection). Consider rabies prophylaxis for bites from animals in endemic countries. Assess risk of blood-borne viruses (including HIV, hepatitis B and C) and give appropriate prophylaxis to prevent viral spread. . Co-amoxiclav . If penicillin-allergic, doxycycline + metronidazole Mastitis during breast-feeding Treat if severe, if systemically unwell, if nipple fissure present, if symptoms do not improve after 12–24 hours of effective milk removal, or if culture indicates infection. Continue breast-feeding or expressing milk during treatment. . Flucloxacillin p. 586 ▶Suggested duration of treatment 10–14 days. . If penicillin-allergic, erythromycin p. 569 ▶Suggested duration of treatment 10–14 days. Useful Resources Cellulitis and erysipelas: antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 141. September 2019. www.nice.org.uk/guidance/ng141 Impetigo: antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 153. February 2020. www.nice.org.uk/guidance/ng153 Leg ulcer infection: antimicrobial prescribing. National Institute for Health and Care Excellence. NICE guideline 152. February 2020. www.nice.org.uk/guidance/ng152 ANTIBACTERIALS › AMINOGLYCOSIDES Aminoglycosides Overview These include amikacin p. 544, gentamicin p. 545, neomycin sulfate p. 546, streptomycin p. 546, and tobramycin p. 546. All are bactericidal and active against some Gram-positive and many Gram-negative organisms. Amikacin, gentamicin, and tobramycin are also active against Pseudomonas aeruginosa; streptomycin is active against Mycobacterium tuberculosis and is now almost entirely reserved for tuberculosis. The aminoglycosides are not absorbed from the gut (although there is a risk of absorption in inflammatory bowel disease and liver failure) and must therefore be given by injection for systemic infections. Gentamicin is the aminoglycoside of choice in the UK and is used widely for the treatment of serious infections. It has a broad spectrum but is inactive against anaerobes and has poor activity against haemolytic streptococci and pneumococci. When used for the ‘blind’ therapy of undiagnosed serious infections it is usually given in conjunction with a penicillin or metronidazole p. 572 (or both). Gentamicin is used together with another antibiotic for the treatment of endocarditis. Streptomycin may be used as an alternative in gentamicin-resistant enterococcal endocarditis. Loading and maintenance doses of gentamicin may be calculated on the basis of the patient’s weight and renal function (e.g. using a nomogram); adjustments are then made according to serum-gentamicin concentrations. High doses are occasionally indicated for serious infections, Infection especially in the neonate, in the patient with cystic fibrosis, or in the immunocompromised patient. Whenever possible treatment should not exceed 7 days. Amikacin is more stable than gentamicin to enzyme inactivation. Amikacin is used in the treatment of serious infections caused by gentamicin-resistant Gram-negative bacilli. Tobramycin has similar activity to gentamicin. It is slightly more active against Ps. aeruginosa but shows less activity against certain other Gram-negative bacteria. Tobramycin can be administered by nebuliser or by inhalation of powder on a cyclical basis (28 days of tobramycin followed by a 28-day tobramycin-free interval) for the treatment of chronic pulmonary Ps. aeruginosa infection in cystic fibrosis; however, resistance may develop and some patients do not respond to treatment. Neomycin sulfate is too toxic for parenteral administration and can only be used for infections of the skin or mucous membranes or to reduce the bacterial population of the colon prior to bowel surgery or in hepatic failure. Oral administration may lead to malabsorption. Small amounts of neomycin sulfate may be absorbed from the gut in patients with hepatic failure and, as these patients may also be uraemic, cumulation may occur with resultant ototoxicity. Once daily dosage Once daily administration of aminoglycosides is more convenient, provides adequate serum concentrations, and in many cases has largely superseded multiple-daily dose regimens (given in 2–3 divided doses during the 24 hours). Local guidelines on dosage and serum concentrations should be consulted. A once-daily, high-dose regimen of an aminoglycoside should be avoided in patients with endocarditis due to Gram-positive bacteria, HACEK endocarditis, burns of more than 20% of the total body surface area, or creatinine clearance less than 20 mL/minute. There is insufficient evidence to recommend a once daily, high-dose regimen of an aminoglycoside in pregnancy. Serum concentrations Serum concentration monitoring avoids both excessive and subtherapeutic concentrations thus preventing toxicity and ensuring efficacy. Serum-aminoglycoside concentrations should be monitored in patients receiving parenteral aminoglycosides and must be determined in the elderly, in obesity, and in cystic fibrosis, or if high doses are being given, or if there is renal impairment. Aminoglycosides (by injection) f
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100 mg every 8 hours for 5–7 days
First-line fragment. Read the complete Indications and Dose section above.
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