Each week we will aim to bring out a concise email that provides 4-5 key pieces of information addressing a specific issue in clinical therapeutics.
This week: Drugs and diarrhoea (part 2)
Diagnostic accuracy is important when considering management of diarrhoea. Chronic diarrhoea is often nonspecific, not necessarily associated with pain, and may be a symptom of many conditions including gastrointestinal malignancy, malabsorption syndromes, intestinal infections and infestations, dietary intolerances (e.g. lactose/wheat), overflow diarrhoea in faecal impaction, inflammatory bowel disease (e.g. Crohn’s colitis), irritable bowel syndrome – diarrhoea predominant, bacterial overgrowth (e.g. due to antibiotics), or radiotherapy to the pelvic/rectal area. Diarrhoea may be associated with anxiety, stress, changes in food or medications. Alarm symptoms such as weight loss or rectal bleeding warrant further investigation.
- Various antimotility agents can be used for the management of diarrhoea. Treatment should be discontinued if abdominal distention occurs, because of risk of toxic megacolon. Agents that can be used for antimotility purposes include:
- loperamide (Imodium®, Gastrostop®) 4 mg initially then 2 mg after each loose bowel motion, maximum 16 mg (8 capsules) daily.
- diphenoxylate 2.5mg/atropine 25mg (Lomotil®) 2-3 tabs 3-4 times daily – not recommended for the elderly because of anticholinergic effects
- codeine phosphate 30-60mg up to 4 times daily – should not be used long term because of opioid dependence issues
- A range of different agents may be used for the purpose of increasing the consistency of bowel motions:
- bulk-forming agents (Metamucil®, Fybogel®) control faecal consistency
- cholestyramine absorbs fluid and is particularly effective in bile salt diarrhoea: the standard dose if 4 – 8 g twice daily. The sandy texture may prove unpalatable to some. Sachets can be mixed in juice or water some hours before use and refrigerated. •
- adsorbents such as kaolin and pectin are no longer routinely recommended
Please consider these issues when preparing or interpreting RMMR reports or education sessions. Contributions of content or suggested topics are welcome and should be sent directly to firstname.lastname@example.org.