The effect of food on ranitidine-induced inhibition of nocturnal gastric secretion

Abstract

Overnight gastric secretion of acid and pepsin was studied in nine, healthy, male volunteers on two separate occasions, in randomized order. On one day, each individual received a standard meal at 18.00 hours, followed by an oral dose of 300 mg ranitidine at 18.15 hours. During the second study, 300 mg ranitidine was again taken at 18.15 hours, but the meal was consumed at 22.00 hours. Gastric juice was sampled hourly from 19.00 to 24.00 hours and then aspirated completely and continuously until 08.00 hours the next morning. Median pH values were significantly lower and median acidity was significantly higher, when the meal was eaten at 22.00 hours. The outputs of acid and pepsin after midnight were also significantly greater following the late night meal. It seems that food interferes with the gastric inhibitory effects of the currently used H2-receptor antagonists, such as ranitidine. We conclude that H2-receptor antagonists must be taken after the last meal of the day in order to ensure maximal therapeutic efficacy.