Erythromycin accelerates gastric emptying in a dose-response manner in healthy subjects

Study Objectives. To evaluate whether a dose-response curve exists for erythromycin, determine the lowest effective dose of erythromycin needed to improve gastric motility, and compare erythromycin's effectiveness with that of metoclopramide in improving gastric emptying. Design. Randomized, crossover, multiintervention trial. Setting. Inpatient clinical research center. Subjects. Ten healthy volunteers (four men, six women) from the general population. Intervention. On each study day, the subjects were infused with erythromycin 0.75 mg/kg, 1.5 mg/kg, or 3.0 mg/kg metoclopramide 10 mg; or placebo, in random order. Subjects then drank Ensure 200 ml mixed with acetaminophen 1.5 g. Gastric emptying was estimated by comparing the area under the curve after 60 minutes for acetaminophen absorption using four timed blood draws. Measurements and Main Results. Erythromycin increased gastric emptying in a dose-response manner. Erythromycin 3.0 mg/kg and metoclopramide 10 mg were associated with statistically significant increases in liquid gastric emptying compared with placebo. During infusion, nausea and stomach cramping were associated with the 3.0-mg/kg dose of erythromycin; drowsiness was associated with metoclopramide. Conclusion. In patients requiring intravenous erythromycin for gastric motility, the 3.0-mg/kg dose seems the most effective, with a reasonable side effect profile.