THE EFFECTS OF ETHANOL ON THE CLEARANCE OF ESTRADIOL IN POSTMENOPAUSAL WOMEN

Objective: To determine whether acute alcohol ingestion affects the pattern of decline of circulating E(2) levels after removal of transdermal E(2) patches. Design: A randomized, placebo-controlled, crossover study. Setting: The study was performed in the Clinical Research Center of the Brigham and Women's Hospital. Participants: Twelve healthy postmenopausal women were enrolled. Interventions: Transdermal E(2) patches, 0.15 mg, were applied 13 hours before subjects ingested alcohol (1 mL/kg 95% ethanol) or carbohydrate placebo punch. The patches were removed immediately after drink ingestion. Main Outcome Measures: Estradiol, estrone (E(1)), and ethanol levels were measured. Results: Serum samples were obtained for 40 minutes before drink ingestion and 5 hours after drink ingestion and E(2) patch removal. At the time of patch removal, E(2) levels rose acutely over 10 minutes and then decreased rapidly, suggesting a bolus effect that was more marked after ethanol ingestion. After ethanol ingestion and patch removal the half-life of E(2) was calculated to be 378 minutes, and after carbohydrate punch and patch removal 245 minutes. There were no significant changes in E(1) concentrations over the time course of the study between groups. Conclusions: Ethanol ingestion may decrease E(2) clearance after removal of transdermal E(2) patches.