An acute elevation in estradiol during alcohol intake has been reported in
postmenopausal women on estrogen replacement therapy. The objective of the
present study was to investigate the acute and long-term effect of alcohol
on ethinylestradiol, the estrogen component found in most oral contraceptiv
es. Nine healthy premenopausal women with regular use of an oral contracept
ive containing 30 mug ethinylestradiol and 75 mug gestodene were challenged
with alcohol (0.4 g/kg p.o., approximately 2-3 standard drinks) 2 h after
intake of the oral contraceptive pill at menstrual cycle day 14. Blood samp
les were taken at 0, 2, 3, 4, 5, and 6 h from intake of alcohol. The challe
nge was repeated after a 7-day period of controlled alcohol intake (0.8 g/k
g/day) at cycle day 21. The same experiments were carried out during placeb
o conditions. At day 21 an increase in the alcohol elimination rate was obs
erved compared with day 14. No significant acute or long-term effect of alc
ohol on ethinylestradiol was found. The lack of an acute effect comparable
to that reported for estradiol may be due to the protection of the ethinyl
group at the 17-position of ethinylestradiol. (C) 2001 Elsevier Science Inc
. All rights reserved.