gastrins and nalmefene

We evaluated whether nalmefene, an orally administered opiate-receptor antagonist, would inhibit gastric acid secretion in response to a meal in healthy humans. On separate days either 50 mg nalmefene or a placebo tablet was administered by mouth 90 min before a blenderized steak meal was infused into the stomach through a nasogastric tube. Compared to placebo, nalmefene inhibited meal-stimulated acid secretion in each of 6 subjects studied (P less than 0.05). During the second and third hours after the meal, nalmefene inhibited mean acid secretion by 16%. Nalmefene also resulted in significantly higher meal-stimulated serum gastrin concentrations than placebo (P less than 0.05) even though intragastric pH was kept constant at 5.0 in both experiments. These studies indicate that an orally administered opiate-receptor antagonist can inhibit gastric acid secretion in response to a meal in humans, yet increase meal-stimulated serum gastrin concentrations.

Topics: Adult; Appetite Depressants; Eating; Female; Gastric Acid; Gastric Juice; Gastrins; Humans; Kinetics; Male; Naltrexone; Placebos; Time Factors