Erythromycin, motilin, and the esophagus.

Abstract

Motilin induces phase III activity of the gastroesophageal tract. Erythromycin has a motilin-like effect on the stomach, but possible esophageal effects have not been evaluated and are the focus of our investigation. Esophageal manometry was performed in 11 healthy volunteers before and after intravenous infusion of 500 mg erythromycin. Values are expressed as means +/- SEM. Lower esophageal sphincter (LES) pressure increased from 21.1 +/- 2.6 mm Hg at baseline to 37.5 +/- 3.8 mm Hg after erythromycin infusion (p < 0.0001). Erythromycin did not affect LES length, esophageal body contraction amplitude, duration or velocity, or the upper esophageal sphincter. Serum motilin levels decreased from 96.4 +/- 10.9 pmol/L to 81.8 +/- 10.9 pmol/L (p < 0.01) after erythromycin administration. Erythromycin profoundly stimulates the normal human LES. This is a direct motilin agonist-like effect and is not mediated by release of endogenous motilin. Erythromycin has no important effect on the esophageal body or the upper esophageal sphincter.