Alcohol interactions with benzodiazepines and cocaine

A rational management of alcoholic patients requires an understanding of alcohol interactions with other drugs. In this discussion, the influence of alcohol on benzodiazepine and cocaine metabolism is examined. The effect of alcohol may be indirect by producing liver disease and secondary impairment of drug metabolism, or direct following acute or chronic alcohol administration. The acute administration of alcohol suppresses the oxidative metabolism of chlordiazepoxide and diazepam and their principal metabolites. This finding may account partly for the enhanced psychomotor impairment following combined benzodiazepine-alcohol ingestion. The conjugation of lorazepam is also decreased, but for unclear reasons that of oxazepam remains normal. Data are insufficient to establish the effect of chronic alcohol administration on benzodiazepine disposition, especially in man. On the other hand, with respect to cocaine, chronic alcohol exposure causes induction of hepatic microsomal enzyme activity and enhances the production of metabolites that prove injurious to the liver, thereby augmenting the hepatotoxic effect of alcohol.