The effect of mild alcohol consumption on the metabolism of acetaminophen in man.

Previous studies with human subjects have shown that chronic alcohol consumption increases the risk of hepatotoxic effects from an overdose of acetaminophen (APAP). Recent studies in humans and with animal models have shown, on the other hand, that an acute dose of alcohol inhibits the development of hepatotoxic effects from an APAP overdose. Our studies in human subjects show that low doses of alcohol consumption may also provide some protection from the hepatotoxicity of APAP overdose. Specifically, we observe that a small dose of alcohol (the equivalent of 1 ounce of ethanol), consumed over a period of one hour prior to the ingestion of APAP, leads to a reduction in APAP-mercapturic acid excretion. The reduction in the excretion of this metabolite extends for a period of up to 12 hours after APAP ingestion, which is longer than the half-life of the alcohol consumed. The changes in APAP-mercapturic acid excretion are easily detected by our chromatography system via a colorimetric reaction with diphenylpicrylhydrazyl (DPPH).