Effect of atropine on gastro-oesophageal reflux and transient lower oesophageal sphincter relaxations in patients with gastro-oesophageal reflux disease.

BACKGROUND Atropine reduces the rate of reflux episodes in normal subjects by inhibition of transient lower oesophageal sphincter (LOS) relaxations. The aim of this study was to investigate the effect of atropine on the rate and mechanisms of reflux in patients with reflux disease. METHODS Oesophageal motility and pH were recorded for one hour after a meal in 15 patients with reflux disease. On separate days, atropine (15 micrograms/kg bolus intravenously, 4 micrograms/kg/h infusion) or saline were given and maintained for the recording period. RESULTS Atropine significantly reduced basal LOS pressure from 7.1 (2.2) to 2.9 (1.3) mm Hg (mean (SEM)). Atropine also reduced the rate of reflux episodes from 5.0 (2.0-8.75) to 1.0 (0-6.25) per hour (median (interquartile range)) largely because of a decrease in the rate of transient LOS relaxations from 2.0 (0-4.75) to 0 (0-0) per hour and abolition of reflux during swallow induced LOS relaxation. There was no change in the rate of reflux episodes because of absent basal LOS pressure. CONCLUSIONS Atropine inhibits reflux in patients with reflux disease largely by inhibition of transient LOS relaxations and swallow induced LOS relaxation. These findings suggest that pharmacological control of reflux through control of transient LOS relaxations is possible in patients with reflux disease.