InternPractice — Always a Step Ahead

Overview

Indications And Dose

Enhance permeation of subcutaneous or intramuscular injections ▶BY SUBCUTANEOUS INJECTION, OR BY INTRAMUSCULAR INJECTION ▶Adult: 1500 units, to be dissolved directly into the solution to be injected (ensure compatibility) continued → Enhance permeation of local anaesthetics ▶BY LOCAL INFILTRATION ▶Adult: 1500 units, to be mixed with the local anaesthetic solution Enhance permeation of ophthalmic local anaesthetic ▶TO THE EYE ▶Adult: 15 units/mL, to be mixed with the local anaesthetic solution Hypodermoclysis ▶BY SUBCUTANEOUS INJECTION ▶Adult: 1500 units, to be dissolved in 1 mL water for injections or 0.9% sodium chloride injection, administered before start of 500–1000 mL infusion ﬂuid Extravasation Musculoskeletal system ▶BY LOCAL INFILTRATION ▶Adult: 1500 units, to be dissolved in 1 mL water for injections or 0.9% sodium chloride and inﬁltrated into affected area as soon as possible after extravasation Haematoma ▶BY LOCAL INFILTRATION ▶Adult: 1500 units, to be dissolved in 1 mL water for injections or 0.9% sodium chloride and inﬁltrated into affected area

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Contra Indications

Avoid sites where infection is present. avoid sites where malignancy is present. do not apply direct to cornea. not for anaesthesia in unexplained premature labour. not for intravenous administration. not to be used to enhance the absorption and dispersion of dopamine and/or alpha-adrenoceptor agonists. not to be used to reduce swelling of bites. not to be used to reduce swelling of stings

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Cautions

▶When used for hypodermoclysis elderly (control speed and total volume and avoid overhydration especially in renal impairment)

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Safety

Side Effects

Oedema. periorbital oedema

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Dose and formulations

Medicinal Forms

There can be variation in the licensing of different medicines containing the same drug. Powder for solution for injection ▶Hyaluronidase (Non-proprietary) Hyaluronidase 1500 unit Hyaluronidase 1,500unit powder for solution for injection ampoules | 10 ampoule P £136.55 Chapter 11 Eye CONTENTS Allergic and inflammatory eye conditions page 1222 Allergic conjunctivitis 1.1 Inﬂammatory eye conditions 1.2 1.2a Anterior uveitis Dry eye conditions Eye infections Bacterial eye infection 3.1 Viral eye infection 3.2 3.2a Ophthalmic herpes simplex Eye Eye treatment: drug administration Drugs are most commonly administered to the eye by topical application as eye drops or eye ointments. When a higher drug concentration is required within the eye, a local injection may be necessary. Eye-drop dispenser devices are available to aid the instillation of eye drops from plastic bottles and some are prescribable on the NHS (consult Drug Tariff—see Appliances and Reagents). Product-speciﬁc devices may be supplied by manufacturers—consult individual manufacturers for information. They are particularly useful for the elderly, visually impaired, arthritic, or otherwise physically limited patients. Eye drops and eye ointments Eye drops are generally instilled into the pocket formed by gently pulling down the lower eyelid and keeping the eye closed for as long as possible after application; one drop is all that is needed. Instillation of more than one drop should be discouraged because it may increase systemic side-effects. A small amount of eye ointment is applied similarly; the ointment melts rapidly and blinking helps to spread it. When two different eye-drop preparations are used at the same time of day, dilution and overﬂow may occur when one immediately follows the other. The patient should therefore leave an interval of at least 5 minutes between the two; the interval should be extended when eye drops with a prolonged contact time, such as gels and suspensions, are used. Eye ointment should be applied after drops. Systemic effects may arise from absorption of drugs into the general circulation from conjunctival vessels or from the nasal mucosa after the excess preparation has drained down through the tear ducts. The extent of systemic absorption following ocular administration is highly variable; nasal drainage of drugs is associated with eye drops much more often than with eye ointments. Pressure on the lacrimal punctum for at least a minute after applying eye drops reduces nasolacrimal drainage and therefore decreases systemic absorption from the nasal mucosa. After using eye drops or eye ointments, patients should be warned not to drive or perform other skilled tasks until vision is clear. Also see warnings relating to eye drops and contact lenses. Eye lotions These are solutions for the irrigation of the conjunctival sac. They act mechanically to ﬂush out irritants or foreign bodies Eye procedures page 1238 Post-operative pain and inﬂammation 4.1 Glaucoma and ocular hypertension Retinal disorders Macular degeneration 6.1 Eye Macular oedema 6.2 Optic neuropathy 6.3 Vitreomacular traction 6.4 as a ﬁrst-aid treatment. Sterile sodium chloride 0.9% solution p. 1232 is usually used. Clean water will sufﬁce in an emergency. Other preparations administered to the eye Subconjunctival injection may be used to administer anti- infective drugs, mydriatics, or corticosteroids for conditions not responding to topical therapy; intracameral and intravitreal routes can also be used to administer certain drugs, for example antibacterials. These injections should only be used under specialist supervision. Drugs such as antimicrobials and corticosteroids may be administered systemically to treat susceptible eye conditions. Ophthalmic Specials Certain eye drops, e.g. amphotericin p. 629, ceftazidime p. 555, cefuroxime p. 1235, colistimethate sodium p. 588, desferrioxamine mesilate p. 1088, dexamethasone p. 1225, gentamicin p. 1234, and vancomycin p. 562 can be prepared aseptically from material supplied for injection. The Royal College of Ophthalmologists and the UK Ophthalmic Pharmacy Group have produced the Ophthalmic Specials Guidance to help prescribers and pharmacists manage and restrict the use of unlicensed eye preparations. ‘Specials’ should only be prescribed in situations where a licensed product is not suitable for a patient’s needs. The Ophthalmic Specials Guidance can be accessed on the Royal College of Ophthalmologists website (www.rcophth.ac.uk). The guidance will be reviewed every six months to ensure the most accurate and up-to-date information is available. Preservatives and sensitisers Information on preservatives and substances identiﬁed as skin sensitisers is provided under Excipients statements in preparation entries. Very rarely, cases of corneal calciﬁcation have been reported with the use of phosphate-containing eye drops in patients with signiﬁcantly damaged corneas— consult product literature for further information. Eye preparations: control of microbial contamination Preparations for the eye should be sterile when issued. Care should be taken to avoid contamination of the contents during use. Eye drops in multiple-application containers for domiciliary use should not be used for more than 4 weeks after ﬁrst opening (unless otherwise stated by the manufacturer). Multiple application eye drops for use in hospital wards are normally discarded 1 week after ﬁrst opening—local practice may vary. Individual containers should be provided for each patient. A separate container should be supplied for each eye only if there are special concerns about contamination. Containers used before an eye operation should be discarded at the time of the operation and fresh containers supplied postoperatively. A fresh supply should also be provided upon discharge from hospital; in specialist ophthalmology units, it may be acceptable to issue containers that have been dispensed to the patient on the day of discharge. In out-patient departments single-application containers should be used; if multiple-application containers are used, they should be discarded after single patient use within one clinical session. In eye surgery single-application containers should be used if possible; if a multiple-application container is used, it Eye should be discarded after single use. Preparations used during intra-ocular procedures and others that may penetrate into the anterior chamber must be isotonic and without preservatives and buffered if necessary to a neutral pH. Specially formulated ﬂuids should be used for intra- ocular surgery; intravenous infusion preparations are not usually suitable for this purpose (Hartmann’s solution may be used in some ocular surgery). For all surgical procedures, a previously unopened container is used for each patient. Contact lenses For cosmetic reasons many people prefer to wear contact lenses rather than spectacles; contact lenses are also sometimes required for medical indications. Visual defects are corrected by either rigid (‘hard’ or gas permeable) lenses or soft (hydrogel or silicone hydrogel—in adults only) lenses; soft lenses are the most popular type, because they are initially the most comfortable, but they may not give the best vision. Lenses should usually be worn for a speciﬁed number of hours each day and removed for sleeping. The risk of infectious and non-infectious keratitis is increased by extended continuous contact lens wear, which is not recommended, except when medically indicated. Contact lenses require meticulous care. Poor compliance with directions for use, and with daily cleaning and disinfection, can result in complications including ulcerative keratitis or conjunctivitis. One-day disposable lenses, which are worn only once and therefore require no disinfection or cleaning, are becoming increasingly popular. Acanthamoeba keratitis, a painful and sight-threatening condition, is associated with ineffective lens cleaning and disinfection, the use of contaminated lens cases, or tap water coming into contact with the lenses. The condition is especially associated with the use of soft lenses (including frequently replaced lenses) and should be treated by specialists. Contact lenses and drug treatment Special care is required in prescribing eye preparations for contact lens users. Some drugs and preservatives in eye preparations can accumulate in hydrogel lenses and may induce toxic and adverse reactions. Therefore, unless medically indicated, the lenses should be removed before instillation of the eye preparation and not worn during the period of treatment. Alternatively, unpreserved drops can be used. Eye drops may, however, be instilled while patients are wearing rigid corneal contact lenses. Ointment preparations should never be used in conjunction with contact lens wear; oily eye drops should also be avoided. Many drugs given systemically can also have adverse effects on contact lens wear. These include oral contraceptives (particularly those with a higher oestrogen content), drugs which reduce blink rate (e.g. anxiolytics, hypnotics, antihistamines, and muscle relaxants), drugs which reduce lacrimation (e.g. antihistamines, antimuscarinics, phenothiazines and related drugs, some beta-blockers, diuretics, and tricyclic antidepressants), and drugs which increase lacrimation (including ephedrine hydrochloride p. 286 and hydralazine hydrochloride p. 192). Other drugs that may affect contact lens wear are isotretinoin p. 1337 (can cause conjunctival inﬂammation), aspirin p. 130 (salicylic acid appears in tears and can be absorbed by contact lenses—leading to irritation), and rifampicin p. 615 and sulfasalazine p. 47 (can discolour lenses). Allergic and inﬂammatory eye conditions Eye, allergy and inflammation Corticosteroids Corticosteroids administered locally to the eye or given by mouth are effective for treating anterior segment inﬂammation, including that which results from surgery. Topical corticosteroids are applied frequently for the ﬁrst 24–48 hours; once inﬂammation is controlled, the frequency of application is reduced. They should normally only be used under expert supervision; three main dangers are associated with their use: . a ‘red eye’, when the diagnosis is unconﬁrmed, may be due to herpes simplex virus, and a corticosteroid may aggravate the condition, leading to corneal ulceration, with possible damage to vision and even loss of the eye. Bacterial, fungal, and amoebic infections pose a similar hazard; . ‘steroid glaucoma’ can follow the use of corticosteroid eye preparations in susceptible individuals; . a ‘steroid cataract’ can follow prolonged use. Combination products containing a corticosteroid with an anti-infective drug are sometimes used after ocular surgery to reduce inﬂammation and prevent infection; use of combination products is otherwise rarely justiﬁed. Systemic corticosteroids may be useful for ocular conditions. The risk of producing a ‘steroid cataract’ increases with the dose and duration of corticosteroid use. Intravitreal corticosteroids An intravitreal implant containing dexamethasone p. 1225 (Ozurdex ®) is licensed for the treatment of adults with macular oedema following either branch retinal vein occlusion or central retinal vein occlusion; it is also licensed for the treatment of adult patients with inﬂammation of the posterior segment of the eye presenting as non-infectious uveitis. An intravitreal implant containing ﬂuocinolone acetonide (Iluvien ®) p. 1256 is licensed for the treatment of visual impairment associated with chronic diabetic macular oedema which is insufﬁciently responsive to available therapies; it is also licensed for the prevention of relapse in recurrent non-infectious uveitis affecting the posterior segment of the eye. It should be administered by specialists experienced in the use of intravitreal injections. Eye care, other anti-inflammatory preparations Other preparations used for the topical treatment of inﬂammation and allergic conjunctivitis include antihistamines, lodoxamide p. 1224, and sodium cromoglicate p. 1224. Eye drops containing antihistamines, such as antazoline (with xylometazoline hydrochloride p. 1267 as Otrivine- Antistin ®), azelastine hydrochloride p. 1223, epinastine hydrochloride p. 1223, ketotifen p. 1223, and olopatadine p. 1224, can be used for allergic conjunctivitis. Sodium cromoglicate (sodium cromoglycate) and nedocromil sodium eye drops p. 1224 can be useful for vernal keratoconjunctivitis and other allergic forms of conjunctivitis. Lodoxamide eye drops are used for allergic conjunctival conditions including seasonal allergic conjunctivitis. Diclofenac sodium eye drops p. 1241 are also licensed for seasonal allergic conjunctivitis. Non-steroidal anti-inﬂammatory eye drops are used for the prophylaxis and treatment of inﬂammation of the eye following surgery or laser treatment. Ciclosporin p. 1228 is licensed for severe keratitis in patients with dry eye disease, which has not improved despite treatment with tear substitutes. Cenegermin p. 1228 is licensed for moderate to severe neurotrophic keratitis. Allergic conjunctivitis 1.1 Other drugs used for Allergic conjunctivitis Diclofenac sodium, p. 1241 ANTIHISTAMINES

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