Comparison of effects of nifedipine, propantheline bromide, and the combination on esophageal motor function in normal volunteers

Abstract
Both intracellular calcium ions and neural input are important in esophageal smooth muscle contraction. The aim of this study was to compare the effects of well-tolerated doses of the calcium-channel blocker, nifedipine (20 mg sublingually/buccally) with the anticholinergic, propantheline bromide (15 mg orally) and the combination of these two agents on esophageal motor function. Seven healthy volunteers underwent manometric evaluation after nifedipine, propantheline bromide, the combination, and placebo on different days. Lower esophageal sphincter pressure decreased significantly (PPP<0.05 vs basal and placebo) by 26% after propantheline bromide, but fell only 11% after nifedipine. The combination led to a decrease of 37% in contraction amplitude, but this was not significantly different from that obtained with propantheline bromide alone. No drug or combination had any effect on other manometric parameters. These data show that in the normal subjects studied with the above doses: (1) nifedipine has a greater effect than propantheline bromide on the lower esophageal sphincter; (2) propantheline bromide has a greater effect than nifedipine on esophageal contraction amplitude; and (3) the combination of nifedipine and propantheline bromide has an enhanced effect on both lower esophageal sphincter pressure and esophageal contraction amplitude.