Effect of sumatriptan, a 5HT(1) agonist, on the frequency of transient lower esophageal sphincter relaxations and gastroesophageal reflux in healthy subjects

OBJECTIVE: Meals increase the rate of transient lower esophageal sphincter (LES) relaxations, in part by gastric distension. The 5HT(1) agonist sumatr iptan reduces fasting fundic tone, prolongs the meal-induced fundic relaxat ion, and delays gastric emptying. We therefore hypothesized that sumatripta n might have a significant effect on the rate of postprandial transient LES relaxations and gastroesophageal reflux. We aimed to study the effect of s umatriptan on postprandial transient LES relaxations and reflux in healthy subjects. METHODS: Esophageal manometry and pH monitoring were performed in 13 health y volunteers for 30 min before and 90 min after a semiliquid meal (790 kcal ). Sumatriptan 6 mg subcutaneous (s.c.) or s.c, placebo were administered o n separate days 30 min after the meal. RESULTS: Sumatriptan significantly increased postprandial LES pressure from 11.0 +/- 1.2 mm Hg to 17.6 +/- 1.2 mm Hg (p < 0.05). However, reflux event s were not diminished. In the contrary, reflux was more frequent after suma triptan than after placebo (3 [1.5-4.5]/30 min res 2 [0-3]/30 min, p < 0.05 ). Transient LES relaxations were more frequent after sumatriptan, particul arly in the second 30-min period after drug administration (3 [2.5-5]/30 mi n cs 2 [1.5-2]/30 min, p < 0.05). CONCLUSIONS: Sumatriptan prevents the natural decay in rate of transient LE S relaxations that occurs after a meal and favors the occurrence of gastroe sophageal reflux despite increasing LES pressure. The sustained postprandia l high rate of transient LES relaxations after sumatriptan may be a consequ ence of a prolonged fundus relaxation and retention of meal in the proximal stomach. (C) 1999 by Am. Cell. of Gastroenterology.