Ethanol Metabolism in Women Taking Oral Contraceptives

Abstract

The relationship between oral contraceptives and ethanol metabolism in women was examined in a group of 40 female social drinkers between the ages of 21 and 30. Twenty women taking oral contraceptives and 20 women not taking oral contraceptives were given a moderate dose of ethanol (0.52 g/kg) during the menstrual, intermenstrual and premenstrual phases of the menstrual cycle. The group of women taking oral contraceptives demonstrated a significantly decreased ethanol elimination rate (105 mg/kg/hr) than the women not taking oral contraceptives (121 mg/kg/hr, p less than .005). Ethanol disappearance rate also was significantly decreased for women taking oral contraceptives (0.015%/hr) than women not taking them (0.019%/hr, p less than .001). These results were consistent across the three phases of the menstrual cycle and when body leanness was taken into consideration. The decreased rate of ethanol metabolism in women taking oral contraceptives is consistent with reports of other drugs having decreased metabolic rates in women taking birth control pills. These results suggest that women taking oral contraceptives should be cautioned concerning their possible interaction with ethanol, as well as other drugs.

Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework

“…However, ethanol is primarily metabolized by cytosolic ADH and not microsomal enzymes, which makes this notion of a drugalcohol interaction rather unlikely. In one test of this hypothesis, the rate of elimination of ethanol from blood was 15 mg/100 mL/h in women on OCS compared with 19 mg/100 mL/h in a control group [169]. By contrast, in another study the rate of elimination of alcohol was faster (22 mg/100 mL/h) after OCS than in a control group of women (15 mg/100 mL/h) [170].…”

Aging accentuates alcohol-induced decrease in protein synthesis in gastrocnemius

“…As a "standard drink" averages 14 g ethanol, humans would have to consume at least 7 standard drinks per day to match that ingested by the alcohol-fed rats. However, this increased intake in rats is also coupled with a several-fold greater rate of alcohol clearance, compared with humans (19,42). As a result, chronic alcohol ingestion in both rats and humans yields comparable circulating alcohol concentrations of 100 -200 mg/ dl.…”

Effects of Menstrual Cycle and Female Sex Steroids on Ethanol Pharmacokinetics

“…In a later, similar study, the same authors found no significant main effects of menstrual cycle on any pharmacokinetic measures. 8 In another laboratory, females tested during the premenstrual phase (day 26) reached lower peak BACs than during menstruation (day 1),l2 and females tested on day 24 reached lower peak BACs and lower disappearance rates than during day l. 9 Sutker et alI3 found that ethanol disappearance rate during the luteal phase (days 20 to 25) was 14% higher than during the early follicular phase (days 2 to 7) and 8% higher than during the ovulatory phase (day 14). Eight additional studies report no differences in ethanol pharmacokinetics across the menstrual c y~l e .~,~, '~-'~ have pointed to several methodological limitations of these prior investigations.…”