Acute gastroenteritis and regular medications

Ask patients with gastroenteritis about their regular medications and comorbidities. Diarrhoea and vomiting may result in reduced absorption of medications, dehydration and reduced oral intake, which can reduce the effectiveness of medications and affect management of comorbidities.

Warn patients that gastroenteritis can reduce the absorption and decrease the effectiveness of some drugs (eg combined oral contraceptives). Consider admitting patients to hospital if reduced absorption of medications may lead to potentially life-threatening complications (eg organ transplant patients taking immunosuppressants, patients with primary adrenal insufficiency [Addison disease] taking corticosteroids).

Some drugs are more likely to cause adverse effects if the patient is dehydrated, not eating, or has an electrolyte imbalance (eg nonsteroidal anti-inflammatory drugs [NSAIDs], angiotensin converting enzyme [ACE] inhibitors, angiotensin II receptor blockers, diuretics, digoxin, warfarin, metformin, lithium). It may be necessary to temporarily stop these drugs to reduce adverse effects secondary to acute gastroenteritis. Consider the risk of stopping the drug versus the adverse effects the patient may experience due to acute gastroenteritis; seek specialist advice if the risk of stopping the drug is high or unclear.

Some drugs require oral intake to avoid adverse effects (eg antihyperglycaemic drugs). For management of adults with diabetes who require adjustments to insulin or antihyperglycaemic treatment during an episode of gastroenteritis, see Sick-day management for adults with diabetes; for children, seek expert advice.