Effect of hyoscine N-butylbromide on gastroesophageal reflux in normal subjects and patients with gastroesophageal reflux disease

OBJECTIVES: Recent studies have shown that atropine reduces gastroesophageal reflux in normal subjects and patients with gastroesophageal reflux. The aim of the study has been to assess the effects of an atropine derivative, hyoscine N-butylbromide in normal subjects and patients with gastroesophageal reflux disease by recording esophageal and gastric pH-metry for a 24-h period. METHODS: Ten normal subjects and 10 patients with gastroesophageal reflux disease were evaluated. PH-metry was performed using two glass pH flexible probes with distal incorporated electrodes. The two catheters were introduced nasally under fluoroscopy. One probe was positioned in the gastric body; the other was placed 5 cm above the lower esophageal sphincter which had been evaluated manometrically before the study. Recording lasted without interruption for 48 h. Patients and normal subjects were assigned to receive hyoscine N-butylbromide (10 mg p.o. t.i.d.) for 24 h followed by a placebo for another 24 h or vice versa in a random manner. The pH was analyzed for a total number of acid refluxes and percentage of the period with pH <4 in the esophagus and the mean gastric pH in 24 h, before and after treatment with hyoscine N-butylbromide. RESULTS: The number of reflux episodes was significantly greater with hyoscine N-butylbromide in comparison with a placebo in patients with gastroesophageal reflux disease and normal subjects (p < 0.02). The percentage of time with pH <4, was also significantly greater in patients with gastroesophageal reflux disease and in controls (p < 0.05). The mean 24-h gastric pH after hyoscine N-butylbromide was not different from placebo in gastroesophageal reflux disease and controls. CONCLUSIONS: Hyoscine N-butylbromide, an anticholinergic agent, increases the total number of esophageal acid refluxes in patients with gastroesophageal reflux disease and in controls, therefore it is not recommended in the treatment of gastroesophageal reflux disease.