Different effects of an oral anticholinergic drug on gastroesophageal reflux in upright and supine position in normal, ambulant subjects: A pilot study

OBJECTIVE: There is controversy in the literature on the effects of anticho linergic drugs on gastroesophageal reflux. Our aim was to study more extens ively the effects of an oral anticholinergic drug on esophageal motility an d gastroesophageal reflux in normal ambulant subjects under differ ent circ umstances: upright, supine, fed, and fasted state. METHODS: Fifteen healthy subjects (seven men, eight women), mean age 34 yr (range, 22-61 yr) underwent randomized placebo-controlled 16-h evening and overnight ambulatory esophageal motility/pH study. After a 3-day loading do se of either oral dicyclomine (Dic) 20 mg four times daily or placebo (Pla) , an ambulatory esophageal motility/pH study was performed while taking med ication or placebo. Each study was analyzed for meal, first and second h po stprandial, upright and supine periods, and first 2 h supine after bedtime snack. RESULTS: The mean number of reflux episodes decreased with dicyclomine duri ng the first h postprandial (Dic, 1.9 vs Pla, 2.5;p < 0.05). During the fir st 2 h supine, mean number of reflux episodes increased with dicyclomine (D ic, 1.4 vs Pla, 0.8; p < 0.09), as did mean percent time pH < 4 (Dic, 2.6 v s Pla, 0.5;p < 0.04), with an increase in clearance time (Dic, 0.9 vs Pla, 0.3; p < 0.05; in min). Mean peristaltic amplitude decreased with dicyclomi ne during the 2nd h postprandial (Dic, 48.8 vs Pla, 56.3; p < 0.04). CONCLUSIONS: Oral dicyclomine caused a decrease in early postprandial uprig ht reflux episodes, but also significantly increased the percent time pH < 4 during the first two h supine. Therefore, its effects are dependent on bo dy position and fasted or fed state. Our results justify additional studies with oral anticholinergic agents in patients with gastroesophageal reflux disease. (C) 1999 by Am. Cell. of Gastroenterology.