Effect of bethanechol on gastroesophageal reflux.

In this study we determined the acute effect of bethanechol (5 mg SC) on gastroesophageal reflux (GER) and lower esophageal sphincter pressure (LESP) in 27 patients with symptomatic esophagitis. The effect of bethanechol on esophageal acid clearance was also determined in 7 of the patients. Intraluminal pH monitoring prior to bethanechol administration demonstrated free or stress-induced reflux episodes in 18 of the 27 patients. Following bethanechol (1) LESP increased significantly, (2) GER diminished or ceased in many of the patients, and (3) acid clearance times decreased significantly. Some individuals, however, continued to reflux despite LESP elevation to 30 mm Hg or more. This latter finding suggests that LESP alone is not the sole factor governing LES competency. Other factors such as improved esophageal emptying may also contribute to the beneficial therapeutic effect of bethanechol in patients with heartburn.