Efficacy of H2 receptor antagonists in the treatment of gastroesophageal reflux disease and its symptoms.

Gastroesophageal reflux disease (GERD) is caused by prolonged esophageal mucosal exposure to acid gastric refluxate due to failure of the normal antireflux mechanisms of the lower esophageal sphincter. Gastroesophageal reflux can be controlled by suppression of acid secretion or by improvement of gastric emptying and esophageal clearance. H2 receptor antagonists are the most commonly used antisecretory drugs, and in the past 20 years have constituted the cornerstone of therapy for the treatment of reflux disease. They have been shown to be effective in the symptomatic treatment of intermittent or mild nonerosive GERD (greater than 70%). When used at the usual recommended dose, all four H2 receptor antagonists (cimetidine, ranitidine, famotidine and nizatidine) are equally effective and are found to be generally very safe; interactions with other drugs metabolized through the cytochrome p450 notwithstanding. However, their efficacy is limited in more severe forms of GERD such as erosive esophagitis (symptomatic improvement 40% to 60%, endoscopic healing 40% to 50%) in which the superior efficacy and more rapid symptomatic relief provided by proton pump inhibitors is clearly demonstrated. The availability of H2 receptor antagonists for over-the-counter use will increase their use for mild and intermittent disease but is unlikely to alter the need for more potent acid suppression in aggressive reflux disease.