The effect of an oral evening dose of nizatidine on nocturnal and peptone-stimulated gastric acid and gastrin secretion.

An evening oral dose of nizatidine, a new H2-receptor antagonist, was tested for its ability to suppress nocturnal gastric acid secretion and to inhibit food stimulated acid secretion the following day. Using a double-blind, randomized, cross-over design, nizatidine 30, 100, and 300 mg and placebo were compared in 8 male subjects with basal acid secretion greater than or equal to 3 mmol/h. Continuous nasogastric suction was started 2 h after oral dosing, and acid secretion was measured hourly overnight. Phenol red was used to determine the completeness of gastric aspiration. The following day, food stimulated acid secretion in response to 8% peptone meals was measured by intragastric titration to determine the carry-over effect of nizatidine. Serum gastrin levels were measured by RIA. Nizatidine inhibited overnight acid secretion in a dose-related manner with 30, 100, and 300 mg producing 57, 73, and 90% suppression. The effect was long-lasting, with nizatidine 300 mg decreasing acid secretion by 52% 10 h after administration. Peptone stimulated acid secretion on the following day was not inhibited by nizatidine. Gastrin levels did not differ significantly among the treatment groups. Nizatidine's effects on nocturnal acid secretion therefore resemble other H2-receptor antagonists.