Influence of cisapride, metoclopramide and loperamide on gastric emptying of normal volunteers as measured by means of the area under the curve of the cumulative fraction absorbed-time profiles of paracetamol.

The present study with paracetamol was designed to compare the effects of 40 mg cisapride, 20 mg metoclopramide and 4 mg loperamide given orally on gastric emptying under fasting conditions in normal volunteers. The well known bioavailability parameters of absorption and the area under the curve of the fractional absorbed time profiles up to 30 min were used as an index of gastric emptying. As reflected by the AUC of the fractional absorbed time profiles, it was concluded that pretreatment with cisapride speeded up the gastric emptying under fasting conditions. Tmax was the only normal bioavailability parameter that showed any significant change after cisapride treatment. Pretreatment with therapeutic doses of loperamide and metoclopramide did not significantly modify stomach emptying.