Background: 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.
Methods: Esophageal manometry was performed in 11 healthy volunteers before and after intravenous infusion of 500 mg erythromycin. Values are expressed as means +/- SEM.
Results: 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.
Conclusions: 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.