VOL: 97, ISSUE: 16, PAGE NO: 51
Emma Bryson, BA, RN, DipHE, is a staff nurse, X-ray department, Stirling Royal Infirmary
The UKCC states in the Standards for the Administration of Medicines (1992) that a practitioner will examine the patient’s prescription in the interests of safety and that the dose, method, route and timing of administration relevant to the patient will be considered.
Naysmith and Nicholson (1998) conducted a survey to ascertain the degree of knowledge of nurses who administer drugs via a nasogastric (NG) tube and found that they had poor knowledge bases when it came to this procedure.
It is important to ensure that, if changing from solid to liquid form, the correct bio-equivalent dose is calculated.
Tablets designed to disintegrate and be absorbed quickly are suitable to be crushed or dissolved. These include film- and sugar-coated tablets. Crushing can be done in a pestle and mortar or by dissolving the tablet in a syringe barrel of water; this way all the medication will be delivered. Gelatine capsules can be dissolved in water. Liquids are acceptable in their own form and some thicker ones can be diluted. Table 1 sets out different forms of medications and whether or not they are suitable for administration via the NG tube.
Enteric-coated tablets must not be crushed or dissolved because there is a risk of gastric irritation if the distal tube is in the stomach. Sustained release or anti-neoplastic tablets must not be crushed or dissolved either, as there is a risk of increased toxicity (Gilbar, 1999).
Buccal and sub-lingual drugs are ineffective when crushed or dissolved (Smith, 1997). They can still be given orally, provided there is no oral injury, impaired mental state, dry mouth or copious secretions.
Factors affecting drug interactions
Some drugs can compromise nutritional status and the timing of administration can enhance or interfere with absorption. For example, enteral feeding can reduce the absorption of some drugs, in which case there must be a four-hour gap after feeding and before restarting to allow for this (Naysmith and Nicholson, 1998). Diarrhoea will alter the absorptive properties of medications. Drugs known to interact with food should also be considered to interact with enteral formulas - for example, penicillin, tetracycline and phenytoin (Gilbar, 1999).
Smith (1997) pointed out that most drugs are not licensed for enteral use. Therefore, if a patient has a reaction to the tampered-with drug the pharmaceutical company will not be liable, whereas doctors, nurses and pharmacists would be. Reilly (1998) suggested that all medicines given via an NG tube should be discussed with a pharmacist before administration.
Recommendations for drug administration via the NG tube are as follows:
- Where possible, use liquids and, if changing from liquid to solid or vice versa, ensure that the dose is re-calculated;
- Ensure that tablets can be crushed or dissolved but do not use enteric coated or sustained release forms in this manner;
- Simplify the medication regimen if appropriate, so drugs can be given twice daily;
- Do not add medications while the feed is still running. Stop the feed, flush the tube with water and flush after each drug before starting the feed again. Arrowsmith (1993) and Rollins (1997) stated that the tube must be flushed with 25-30ml of water before and after a feed;
- For drugs to be given on an empty stomach, the feed should be stopped 30 minutes before and after administration;
- Monitor the patient for signs of complications;
- Ask the pharmacist for advice and consider an alternative route if indicated.
Negus (1994) argued that a holistic approach to patients with NG tubes must be taken so that they are involved in their care as much as possible. Nurses must look to local policy for clarification of NG drug administration and liaise with pharmacists, doctors, patients and other nurses to avoid fragmented care.