Indications And Dose
Toxoplasmosis in pregnancy (in combination with sulfadiazine and folinic acid) ▶BY MOUTH ▶Adult: 50 mg once daily until delivery
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Individual generic drug information
Extracted information for Pyrimethamine only.
Toxoplasmosis in pregnancy (in combination with sulfadiazine and folinic acid) ▶BY MOUTH ▶Adult: 50 mg once daily until delivery
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History of seizures—avoid large loading doses. predisposition to folate deficiency
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Extracted information for Pyrimethamine only.
→Appendix 1: antimalarials
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▶Common or very common Anaemia. diarrhoea. dizziness. headache. leucopenia. nausea. skin reactions. thrombocytopenia. vomiting ▶Uncommon Fever ▶Rare or very rare Abdominal pain. oral ulceration. pancytopenia. pneumonia eosinophilic. seizure
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Theoretical teratogenic risk in first trimester (folate antagonist). Adequate folate supplements should be given to the mother.
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Significant amount in milk—avoid administration of other folate antagonists to infant. Avoid breast-feeding during toxoplasmosis treatment.
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Manufacturer advises caution.
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Manufacturer advises caution.
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Blood counts required with prolonged treatment.
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Extracted information for Pyrimethamine only.
There can be variation in the licensing of different medicines containing the same drug. Forms available from special-order manufacturers include: oral suspension Tablet ▶Daraprim (GlaxoSmithKline UK Ltd) Pyrimethamine 25 mg Daraprim 25mg tablets | 30 tablet P £13.00 Viral infection 6.1 Coronavirus COVID-19 Description of condition COVID-19 is the syndrome caused by a novel coronavirus, SARS-CoV-2, which was originally detected late 2019 in Wuhan, Hubei Province, China. Primary transmission between people is through respiratory droplets generated by coughing and sneezing, and through contact with contaminated surfaces. COVID-19 is predominantly a respiratory illness with early non-specific symptoms that can last 2–10 days before more specific signs or symptoms develop. The most common symptoms are fever, cough, and shortness of breath. Other symptoms, such as anxiety, delirium, agitation, fatigue, muscle aches, headache, and a loss of sense of smell may also be present. The illness varies in severity from no symptoms present in some individuals to severe pneumonia in others. Older patients and/or those with co-morbidities (such as chronic obstructive pulmonary disease, cystic fibrosis, asthma, cardiovascular disease, and diabetes), frailty, impaired immunity, or a reduced ability to cough and clear secretions are more likely to develop severe pneumonia. Patients with severe symptoms of COVID-19 may deteriorate rapidly and older patients with co- morbidities may have a higher risk of deteriorating. Management Medical practitioners must notify the Proper Officer at their local council or local health protection team of all suspected cases of COVID-19. For further information, see Notifiable diseases in Antibacterials, principles of therapy p. 527. NICE have developed rapid guidelines to maximise patient safety, optimise treatment management, protect staff from infection, and make the best use of NHS resources. These guidelines provide recommendations around the provision of care during the pandemic (such as critical care in adults and systemic anticancer treatments), and for managing symptoms (including at the end of life) and suspected/confirmed pneumonia. They also include recommendations for patients with conditions that increase the risk of developing COVID-19 (such as in immunocompromised patients; those with severe asthma; cystic fibrosis; rheumatological autoimmune, inflammatory and metabolic bone disorders; or conditions treated with drugs that affect the immune response). NICE are also developing rapid evidence summaries focusing on whether certain medications (such as non-steroidal anti- inflammatory drugs) may increase the severity/length of the COVID-19 illness, and advice on the safety and efficacy of COVID-19 treatments. For further information, see NICE rapid guidelines and evidence summaries: Coronavirus (COVID-19)(see Useful resources). NHS England and NHS Improvement have produced guidance for clinicians and NHS managers working in primary and secondary care, and community-based health, social care, mental health trusts and ambulance services. For further information, see NHS England: Coronavirus guidance for clinicians and NHS managers (see Useful resources). PHE have also produced guidance for health professionals, the public, and those in non-clinical settings; on infection prevention and control; and sampling and diagnostics. For further information, see the PHE collection: Coronavirus (COVID-19): guidance (see Useful resources). The MHRA have issued COVID-19 guidance for industry, in addition to information about medications and COVID-19, and guidance on medical devices (such as COVID-19 tests and testing kits). For further information, see the MHRA collection: MHRA guidance on coronavirus (COVID-19) (see Useful resources). The UKTIS have produced an information page summarising the fetal and neonatal risks of exposure to COVID-19 treatments that have either been identified as possible options or listed as investigational medicinal products. For further information, see UKTIS: Medications used to treat COVID-19 in pregnancy (see Useful resources). The Joint Committee on Vaccination and Immunisation have issued a statement on immunisation prioritisation during the COVID-19 pandemic (available at: www.gov.uk/ government/publications/jcvi-statement-on-immunisation- prioritisation/statement-from-jcvi-on-immunisation- prioritisation). Additional country-specific guidance is available for Northern Ireland, Scotland, and Wales (see Useful resources). Useful Resources Medicines and Healthcare products Regulatory Agency (MHRA). MHRA guidance on coronavirus (COVID-19) collection. www.gov.uk/government/collections/mhra-guidance-on- coronavirus-covid-19 National Health Service England (NHSE) and National Health Service Improvement (NHSI). Coronavirus guidance for clinicians and NHS managers. www.england.nhs.uk/coronavirus/ National Institute for Health and Care Excellence (NICE). Coronavirus (COVID-19) rapid guidelines and evidence summaries. www.nice.org.uk/covid-19 Public Health England (PHE). Coronavirus (COVID-19) collection. www.gov.uk/government/collections/coronavirus-covid-19-list-of- guidance UK Teratology Information Service (UKTIS). Medications used to treat COVID-19 in pregnancy. www.medicinesinpregnancy.org/bumps/monographs/ MEDICATIONS-USED-TO-TREAT-COVID-19-IN-PREGNANCY/ Northern Ireland Government Services. Coronavirus (COVID-19). www.nidirect.gov.uk/campaigns/coronavirus-covid-19 Public Health Agency in Northern Ireland. Coronavirus (COVID-19). www.publichealth.hscni.net/news/covid-19-coronavirus Scottish Government. Coronavirus in Scotland. www.gov.scot/coronavirus-covid-19/ Health Protection Scotland. Coronavirus (COVID-19). www.hps.scot.nhs.uk/a-to-z-of-topics/wuhan-novel-coronavirus/ Welsh Government. Coronavirus (COVID-19). gov.wales/coronavirus Public Health Wales. Novel Coronavirus (COVID-19). phw.nhs.wales/topics/latest-information-on-novel-coronavirus- covid-19/ 6.2 Hepatitis Hepatitis Overview Treatment for viral hepatitis should be initiated by a specialist. The management of uncomplicated acute viral hepatitis is largely symptomatic. Early treatment of acute hepatitis C with interferon alfa p. 1008 [unlicensed indication] may reduce the risk of chronic infection. Hepatitis B and hepatitis C viruses are major causes of chronic hepatitis. Active or passive immunisation against hepatitis A and B infections can be given. Chronic hepatitis B Peginterferon alfa p. 660 is an option for the initial treatment of chronic hepatitis B and may be preferable to interferon alfa. The use of peginterferon alfa and interferon alfa is limited by a response rate of 30–40% and relapse is Infection frequent. Treatment should be discontinued if no improvement occurs after 4 months. The manufacturers of peginterferon alfa-2a and interferon alfa contraindicate use in decompensated liver disease, but low doses can be used with great caution in these patients. Although interferon alfa is contra-indicated in patients receiving immunosuppressant treatment (or who have received it recently), cautious use of peginterferon alfa-2a may be justified in some cases. Entecavir p. 658 or tenofovir disoproxil p. 691 are options for the initial treatment of chronic hepatitis B. If the response is inadequate after 6–9 months of treatment, a change in treatment should be considered. Other drugs that are licensed for the treatment of chronic hepatitis B include adefovir dipivoxil p. 659, lamivudine p. 689, or telbivudine p. 659. Entecavir alone, tenofovir disoproxil alone, or a combination of lamivudine with either adefovir dipivoxil or tenofovir disoproxil can be used in patients with decompensated liver disease. If drug-resistant hepatitis B virus emerges during treatment, another antiviral drug to which the virus is sensitive should be added. Hepatitis B viruses with reduced susceptibility to lamivudine have emerged following extended therapy. Adefovir dipivoxil or tenofovir disoproxil can be given with lamivudine in lamivudine-resistant chronic hepatitis B; telbivudine or entecavir should not be used because cross-resistance can occur. If there is no toxicity or loss in efficacy, treatment with adefovir dipivoxil, entecavir, lamivudine, telbivudine, or tenofovir disoproxil is usually continued until 6 months after adequate seroconversion has occurred. Treatment is usually continued long-term in patients with decompensated liver disease. Tenofovir disoproxil, or a combination of tenofovir disoproxil with either emtricitabine p. 687 or lamivudine may be used with other antiretrovirals, as part of ‘highly active antiretroviral therapy’ in patients who require treatment for both HIV and chronic hepatitis B. If patients infected with both HIV and chronic hepatitis B only require treatment for chronic hepatitis B, they should receive antivirals that are not active against HIV, such as peginterferon alfa or adefovir dipivoxil. Treatment may be continued long-term, even if adequate seroconversion occurs. Management of these patients should be coordinated between HIV and hepatology specialists. Chronic hepatitis C Before starting treatment, the genotype of the infecting hepatitis C virus should be determined and the viral load measured as this may affect the choice and duration of treatment. A combination of ribavirin p. 662 and peginterferon alfa is used for the treatment of chronic hepatitis C. The combination of ribavirin and interferon alfa is less effective than the combination of peginterferon alfa and ribavirin. Peginterferon alfa alone should be used if ribavirin is contra-indicated or not tolerated. Ribavirin monotherapy is ineffective. Daclatasvir is licensed for use in combination with sofosbuvir p. 665 for the treatment of chronic hepatitis C infection of genotypes 1 or 4, with or without compensated cirrhosis; the addition of ribavirin should be considered for patients with advanced liver disease or with other negative prognostic factors, such as prior treatment experience. It is also licensed in combination with sofosbuvir and ribavirin for the treatment of chronic hepatitis C infection of genotype 3 in patients who are treatment experienced, with or without compensated cirrhosis, and in combination with peginterferon alfa and ribavirin for the treatment of chronic hepatitis C infection of genotype 4. Daclatasvir must not be given as monotherapy. Ombitasvir with paritaprevir and ritonavir p. 662 (Viekirax ®), is licensed for use in combination with dasabuvir Infection p. 668, with or without ribavirin, for the treatment of chronic hepatitis C infection of genotype 1 in patients with or without compensated cirrhosis; it is also licensed for use in combination with ribavirin for the treatment of chronic hepatitis C infection of genotype 4 with or without compensated cirrhosis. Ribavirin inhibits a wide range of DNA and RNA viruses. It is given by mouth for the treatment of chronic hepatitis C infection, in double therapy with peginterferon alfa, interferon alfa, or sofosbuvir, or in triple therapy with peginterferon alfa and one protease inhibitor or sofosbuvir. Ribavirin is also effective in Lassa fever [unlicensed indication]. Sofosbuvir is a pro-drug of a nucleoside inhibitor that is effective against hepatitis C virus polymerase NS5B. It is licensed for use in combination with ribavirin, with or without peginterferon alfa, for the treatment of chronic hepatitis C infection of genotypes 1, 2, 3, 4, 5, or 6 in patients with compensated liver disease. Sofosbuvir monotherapy is not recommended because it is less effective than combination therapy. Ledipasvir is licensed for use in combination with sofosbuvir (ledipasvir with sofosbuvir p. 664), with or without ribavirin, for the treatment of chronic hepatitis C infections of genotypes 1, 3, 4, 5 or 6. Sofosbuvir with velpatasvir and voxilaprevir p. 667 is licensed for the treatment of chronic hepatitis C of all genotypes. 6.3 Hepatitis infections 6.3a Chronic hepatitis B Other drugs used for Chronic hepatitis B Interferon alfa, p. 1008. Lamivudine, p. 689. Tenofovir disoproxil, p. 691 ANTIVIRALS › NUCLEOSIDE ANALOGUES
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Filter the extracted dose blocks for this individual drug.
First line only; read the complete Indications and dose section above.
50 mg once daily until delivery
This is a first-line fragment. Read the full Indications and Dose section above.
Candidate age grouping · source page 678