Aspirin increases blood alcohol concentrations in humans after ingestion of ethanol

Any drug that is absorbed from the stomach and intestine must first pass through the liver before reaching the circulation. If the drug is metabolized, such as in the liver, before reaching the circulation, there will be less active drug available to exert its therapeutic effects. The decrease in bioavailability, or availability of a drug at its sites of action, due to its metabolism before reaching the circulation, is known as the first-past effect. Ethanol undergoes oxidation, a metabolic reaction, in the stomach, and this reaction was shown to be an important factor in determining the blood levels of alcohol. Fasting, alcohol abuse, and female gender are associated with diminished first-pass metabolism. Certain drugs, such as cimetidine and ranitidine, used to treat ulcers, also affect first-pass metabolism and gastric alcohol dehydrogenase (ADH), an enzyme involved in alcohol metabolism. Treatment with these agents is associated with elevated blood alcohol levels after ingestion of only small or moderate doses of ethanol. Aspirin, which is commonly used to relieve pain and treat rheumatic disorders, can cause adverse gastrointestinal side effects. The effects of aspirin on ADH and first-pass metabolism of ethanol were assessed in five healthy volunteers given 0.3 grams per kilogram of body weight. Ingestion of one gram of aspirin one hour before alcohol intake was associated with higher blood levels of alcohol in the fed state, defined as one hour after a standard breakfast, as compared with levels in the absence of aspirin ingestion. Aspirin was shown to decrease the activity of ADH in the stomach of humans and experimental rats, but not the activity of rat liver ADH. Aspirin had no effect on blood alcohol levels in rats when alcohol was given directly into the circulation. These findings suggest that aspirin increases the blood levels of alcohol in humans by decreasing the metabolism of ethanol by gastric ADH. (Consumer Summary produced by Reliance Medical Information, Inc.)

author: Baraona, Enrique, Lieber, Charles S., Roine, Risto, Gentry, R. Thomas, Hernandez-Munoz, Rolando

Publisher: American Medical Association
Publication Name: JAMA, The Journal of the American Medical Association
Subject: Health
ISSN: 0098-7484
Year: 1990