Opiate agonists

Opiate agonists in GI

Opioids markedly reduce peristaltic and propulsive motor activity while at the same time increasing pyloric, ileocolic, and anal sphincter tone. They increase segmental contractions of the small and large bowel, prolonging transit and increasing the resistance to flow through the lumen.

Natural opioids such as morphine and codeine are very effective anti-diarrhoeal drugs. Loperamide is a synthetic opioid that has the advantage over classical opioids that it does not cross the blood-brain barrier as readily. Loperamide is used for specific presentations of chronic diarrhoea.


Loperamide is indicated in patients with diarrhoea due to