Drug class · Digestive

Antimotility agents

Also known as: antimotility drugs, anti-diarrhoeal medicines

Antimotility agents are medicines that slow the bowel to treat diarrhoea, and loperamide is the member covered on this site. Product information for UK loperamide medicines says it slows the bowel and increases absorption of water and electrolytes, so stools firm up. The NHS says loperamide slows the passage of food through the gut, which lets the body absorb more water, so stools firm up and become less frequent. The NHS advises talking to a doctor if loperamide bought over the counter is needed for more than a short time.

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Also called
antimotility drugs, anti-diarrhoeal medicines

Mechanism of action

UK and US product information describes loperamide as an opioid (mu) receptor agonist that acts on the gut wall to reduce propulsive movement of the bowel. The slower movement gives the body more time to take water back from the bowel contents.

Members of the class

loperamide

Members with a page on this site are linked.

Conditions treated

Inflammatory bowel disease

Class effects

  • Constipation, headache and feeling sick are common side effects, according to the NHS.
  • Dizziness, tiredness or sleepiness, which alcohol makes more likely

Cautions

  • The NHS lists severe diarrhoea after antibiotics, a flare-up of ulcerative colitis, constipation or a swollen stomach, and blood in the stool with a high temperature as situations where loperamide is not suitable.
  • The NHS says loperamide is not usually recommended in pregnancy because there is not enough evidence about it.
  • The NHS says some medicines can affect how loperamide works, including clozapine, ritonavir, quinidine, itraconazole, gemfibrozil and desmopressin.
  • MedlinePlus says taking more than the recommended amount of loperamide can cause serious heart problems that may be fatal.
  • The NHS says taking too much loperamide can cause serious heart problems. If too much has been taken, 999 or A&E is the route for urgent help; if it was taken on purpose, NHS 111 and Samaritans on 116 123 (free, any time) can also help.
  • MedlinePlus, a US source, says loperamide should not be given to a child younger than 2 years because of the risk of serious breathing and heart problems.
  • MedlinePlus says people with a prolonged QT interval, a slow or irregular heartbeat or low potassium should tell their doctor before using it.
  • The NHS says a serious allergic reaction to loperamide is possible but rare.
  • The NHS advises not driving, cycling or using machinery if loperamide causes dizziness, tiredness or sleepiness.

Class interactions

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Connected pages in detail

What each linked page on Anatomy Nexus covers, in a line, for Antimotility agents.

Conditions

  • Inflammatory bowel disease Chronic inflammation of the gut driven by an abnormal immune response: ulcerative colitis affects the colon's lining continuously from the rectum.

Medications

  • Loperamide Loperamide is a medicine for diarrhoea that slows the activity of the bowel so that stools firm up.
Educational content. A drug class page describes what a family of medicines has in common. Individual medicines differ in dose, licensing and interactions; treatment choices belong to a prescriber.