The effect of cisapride on duodenal acid exposure in the proximal duodenumin healthy subjects

Aim: To investigate the effect of the prokinetic drug, cisapride, on fastin g and postprandial acid exposure in the proximal duodenum, Methods: Using a double-blind, placebo-controlled crossover study design, 1 2 healthy male volunteers were studied. After I week of dosing (cisapride 2 0 mg b.d. orally or placebo), fasting and postprandial antroduodenal pi-I-a nd pressure-recordings were made. Using a small-caliber (4 nlm) catheter, c ontaining one antral and two duodenal pH electrode, and two antral and thre e duodenal pressure recording sites. Transmucosal potential difference was measured to ensure proper catheter position, Infusions of 0.1 N HCl were gi ven in the duodenal bulb, Results: Endogenous acidification of the duodenal bulb occurred more freque ntly during phase II and postprandially, compared to phase I (P < 0.001), D uring phase I, alkalinization of the antrum was observed, Cisapride signifi cantly increased the postprandial number of duodenal acidic periods (P < 0. 02), but shortened their duration (P < 0.04). The duodenal motor response e licited by exogenous acid was lower during phase I (P < 0.05). Conclusions: Antral and proximal duodenal acidity vary with the phases of t he interdigestive motor complex. Cisapride shortens the individual periods of duodenal acidification.