Nursing Practice Drug round Medicines administration

Part two of this four-part series discusses drug reduces the risk 5 key of systemic administration using alternatives to the oral route points side-effects The sublingual Topical 1route provides 4administration rapid drug can also be used to Administration of absorption into administer drugs the systemic into the systemic circulation circulation, for drugs 2: non-oral The rectal example nicotine 2route can be replacement used to administer patches antiemetics to Medicines hile the oral route is most almost directly at the intended site of treat nausea and 5should only frequently used for drug action, and because the systemic circula- vomiting be administered administration, it is not tion is not reached in great concentration, Topical via fine-bore Walways appropriate. In the risk of systemic side-effects is reduced. 3application enteral feeding such situations a range of alternatives is Examples of topical drugs include: allows medicines tubes as a last available to treat the patient effectively. » Eye drops containing beta blockers to to be delivered to resort and other treat glaucoma; the intended site routes should be Sublingual route » Topical steroids to manage dermatitis; of action and considered first The sublingual mucosa offers a rich supply » Inhaled bronchodilators to treat asthma; of blood vessels through which drugs can » Pessaries containing clotrimazole to be absorbed. This is not a common route of treat vaginal candidiasis. administration but it offers rapid absorp- Topical administration has also become tion into the systemic circulation. The a popular way of introducing drugs into most common example of sublingual the systemic circulation through the skin. administration is glyceryl trinitrate in the The development of transdermal patches treatment of acute angina. that contain drugs began with the intro- The pharmaceutical industry has for- duction of a hyoscine-based product for mulated “wafer-based” versions of tablets the treatment of nausea in the early 1980s. that dissolve rapidly under the tongue. The market for such products has since These are aimed at particular groups of grown to include a wide range of therapy patients who have difficulty taking tablets, areas including smoking cessation (nico- such as rizatriptan for people with tine replacement), chronic pain (fentanyl) Eye drops are an example of drugs that migraines that are sometimes accompa- and hormone replacement (oestrogens). can be administered topically nied by symptoms of nausea, which may Transdermal drug administration is not prevent them from taking oral treatments. without its problems – for example, some White and Bradnam (2010) give a good Wafers are also used to treat conditions in preparations can cause local skin reactions overview of this route, while the British which concordance is an issue; for – but many patients find it a welcome Association for Parenteral and Enteral example, olanzapine can be administered alternative to taking tablets. Nutrition has produced a step-by-step by the sublingual route when used to treat guide for administration of drugs via schizophrenia. Administration via enteral enteral feeding tubes as well as informa- feeding tubes tion leaflets for GPs and patients (www. Rectal administration Medicines should only be administered via bapen.org.uk/res_drugs.html). NT The rectal route has considerable disad- fine-bore enteral feeding tubes as a last vantages in terms of patient acceptability resort after other routes have been consid- Martin Shepherd is head of medicines (in the UK at least) and unpredictable drug ered. Most medicines are not licensed for management at Chesterfield Royal Hospital absorption, but it does offer a number of enteral administration and this route is Foundation Trust benefits. Drug delivery can be localised complex from a medico-legal perspective. Further reading into the large bowel – for example, the use Interactions that may compromise the White R, Bradnam V (2010) Handbook of Drug of rectal steroids in the form of enemas or effectiveness of a drug can occur between Administration via Enteral Feeding Tubes. London: suppositories in the treatment of inflam- the drug and the enteral feed. Clinically sig- Pharmaceutical Press. matory bowel disease. nificant interactions include phenytoin, Antiemetics can be administered rec- digoxin, ciprofloxacin and rifampicin. Other articles in this tally to treat nausea and vomiting, and Drugs that have to be specially prepared series paracetamol can be given to treat patients as liquids to enable administration via with a pyrexia who are unable to swallow. enteral tube incur significant additional Part 1 The oral route, 16 August costs, and consideration should be given Part 3 The parenteral route, Topical administration to alternatives before these are requested. 13 September The topical application of medicines has A pharmacist should, therefore, be Part 4 Patient self-administration, obvious advantages in the management of involved in any decision to administer 20 September localised disease. The drug is available medicines via this route. Alamy

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