Interactions between ethanol and oral contraceptive steroids.

Area of Science:

• Pharmacology
• Toxicology
• Women's Health

Background:

• Oral contraceptive steroids (OCSs) are widely used by women of reproductive age.
• The interaction between OCSs and ethanol (alcohol) consumption is not fully understood.
• Investigating the effects of OCSs on ethanol disposition and tolerance is crucial for public health.

Purpose of the Study:

• To determine the impact of oral contraceptive steroids (OCSs) on plasma ethanol concentration and disposition.
• To assess the effect of OCS use on ethanol tolerance and functional impairment in women.
• To compare ethanol effects in light versus moderate drinkers using OCSs and controls.

Main Methods:

• Fifty-four healthy women (18-40 years) were divided into light and moderate drinkers, with subgroups using OCSs (30-50 mcg estrogen) or no OCSs.
• Ethanol (0.9 gm/kg) was administered, and plasma ethanol concentrations were measured for 6 hours.
• Two motor function tests assessed functional performance, with four women serving as their own controls with and without OCS use.

Main Results:

• No significant differences in peak plasma ethanol concentration, time to peak, AUC, or ethanol elimination rate were observed between OCS users and controls.
• All subjects experienced functional impairment, but moderate drinkers showed less impairment than light drinkers, indicating acquired tolerance.
• OCS users exhibited significantly less functional impairment and faster recovery compared to non-users, suggesting an induced tolerance.

Conclusions:

• Oral contraceptive steroid use appears to induce a form of tolerance to ethanol, reducing functional impairment.
• Ethanol disposition (metabolism) is not significantly altered by OCS use, even at high plasma concentrations.
• Women using OCSs should not increase their alcohol intake, as tolerance does not equate to increased safety or capacity.