Cisapride.  A preliminary review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use as a prokinetic agent in gastrointestinal motility disorders. 
Cisapride, a substituted piperidinyl benzamide chemically related to metoclopramide, is an orally administered prokinetic agent which facilitates or restores motility throughout the length of the gastrointestinal tract.  Its novel mechanism of action is thought to involve enhancement of acetylcholine release in the myenteric plexus of the gut.  Because of its specificity cisapride is devoid of central depressant or antidopaminergic effects; side effects such as diarrhoea or loose stools, which occur infrequently, are related to its primary pharmacological action.  Evidence exists from comparisons with placebo in initial trials to establish the efficacy of cisapride in improving healing rates and symptoms in patients with reflux oesophagitis, in alleviating symptoms in patients with non-ulcer dyspepsia, and in accelerating gastric emptying in gastroparesis.  There are less conclusive data regarding the efficacy of cisapride in relieving symptoms in patients with gastroparesis, although preliminary results support a role for cisapride in certain groups such as diabetics.  Limited data suggest that patients with chronic constipation due to underlying motility disorders may benefit from cisapride.  Unfortunately, there is a paucity of trials comparing the efficacy of cisapride with other therapeutic agents.  Thus, the relative position of cisapride in therapy cannot be defined at present.  Should future results support preliminary evidence of comparable efficacy to metoclopramide, domperidone and ranitidine (in oesophagitis), cisapride with its favourable tolerability profile should claim a prominent position in the therapy of patients with a variety of gastrointestinal motility disorders.