What is the mechanism of action of cisapride?

Cisapride acts primarily as a 5-HT4 agonist, which means it stimulates serotonin receptors of the subtype 4. By binding to these receptors in the gastrointestinal tract, cisapride enhances the release of acetylcholine, promoting increased peristalsis and gastrointestinal motility. This action makes it effective in treating conditions such as gastrointestinal stasis or reduced motility disorders.

The effect of cisapride on serotonin receptors contributes to its ability to enhance gastric emptying and improve esophageal motility, which is particularly useful in certain gastrointestinal conditions. The specificity of this action towards 5-HT4 receptors distinguishes it from other classes of drugs that might affect motility or gastric function, leading to its unique therapeutic profile.

Understanding the mechanistic pathway of cisapride is essential, especially when considering its clinical applications and potential side effects, particularly in relation to cardiac arrhythmias resulting from its interaction with other serotonin receptors, such as 5-HT3.