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 E2 levels after removal of transdermal E2 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 E2 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 (E1), and ethanol levels were measured.

RESULTS

Serum samples were obtained for 40 minutes before drink ingestion and 5 hours after drink ingestion and E2 patch removal. At the time of patch removal, E2 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 E2 was calculated to be 378 minutes, and after carbohydrate punch and patch removal 245 minutes. There were no significant changes in E1 concentrations over the time course of the study between groups.

CONCLUSIONS

Ethanol ingestion may decrease E2 clearance after removal of transdermal E2 patches.