Abstract
Background: Erythromycin and neostigmine have both been shown to act as gastrointestinal promotility agents. Objectives: The purpose of this study was to determine whether either erythromycin or neostigmine, administered parenterally, would result in lower serum levels of a recently ingested drug, when compared with placebo. Methods: Ten volunteers ingested 1300 mg of extended‐release acetaminophen on each of three occasions. They were then given an intravenous dose of erythromycin (200 mg), neostigmine (2 mg), or placebo. Each volunteer received all three treatments in a counterbalanced fashion, each separated from the next by at least two weeks. Blood for serum acetaminophen concentration was drawn at 1, 2, 4, 6 and 8 h after treatment, and the serum acetaminophen elimination curves were compared for the three treatments. Results: The elimination phase of the curves did not differ among the treatments as a result of administration of the prokinetic agents. Conclusions: Under the present conditions, administration of erythromycin and neostigmine as prokinetic agents failed to alter the kinetics of an ingested dose of sustained‐release acetaminophen.