The effects of nizatidine on transient lower esophageal sphincter relaxations (TLESRs) and acid reflux in healthy subjects

Abstract

Background: A study in Japan has found that nizatidine (NIZ) is more effective than other histamine H2 receptor agonists (H2RAs) in treating reflux esophagitis (RE), although the NIZ group included a greater number of patients with severe RE. As there was no difference in the level of acid suppression among H2RAs, it is possible that NIZ has other effects on esophageal acid exposure (EAE) besides acid suppression. In this study, the effect of NIZ on transient lower esophageal sphincter relaxations (TLESRs) and acid reflux was evaluated in healthy subjects. Methods: In 10 healthy subjects, while in a sitting position, esophageal motility and a pH study were measured for 3 hours after a meal on 2 separate days at least 2 weeks apart. Participants received an oral dose of 150 mg of NIZ, 60 min before the meal on one day and a placebo on the other. Both studies were preceded by a week of treatment with either NIZ (150 mg, bid) or a placebo and the order of treatment was randomized. Results: Basal LES pressure in the NIZ group (14.1 mmHg, median) was significantly greater than that of the placebo group (8.5 mmHg). The rate of TLESRs in the NIZ group (22.0/3 h) for the postprandial 3-hour period was significantly less than that of the placebo group (16.5/3 h) and the rate of acid reflux during TLESRs (24.7%) and the EAE (0.2%) in the NIZ group for the postprandial 3-hour period was also significantly less than that of the placebo group (74.4% and 2.8%, respectively). Conclusion: NIZ significantly reduces acid reflux by inhibiting both the rate of TLESRs and acid reflux during TLESRs.