Acetaminophen metabolism in recovering alcoholics

The mercapturic acid conjugate of acetaminophen has been proposed as an index of the toxic intermediate of acetaminophen metabolism which is responsible for the increased incidence of liver injury in alcoholics taking the drug. Previous studies which compared alcoholics with normal patients failed to show any significant difference in mercapturic acid production. We undertook a longitudinal study in recovering alcoholics to test the hypothesis that abstinence should lead to a decrease in acetaminophen-mercapturic acid excretion. The patients were given a 1500 mg dose of acetaminophen soon after they stopped drinking then again approximately 2 weeks later. Urine was collected for 24 h and assayed for mercapturic acid conjugate. There was no significant difference in mercapturic acid excretion when the two measurements were compared. If the toxic intermediate hypothesis is correct, either the effect of alcohol is prolonged, or additional factor other than alcohol exposure may influence mercapturic acid excretion.