Ethanol enhances immunosuppression induced by cocaine.

Use of cocaine concurrently with alcohol is prevalent among cocaine addicts. Cocaine has been shown previously to inhibit phytohemagglutinin- and ConA-induced proliferation of T-lymphocytes, NK cell cytotoxicity and phagocytic activity of peritoneal macrophages. We compared the immunotoxic effect of cocaine, combination of cocaine with ethanol, or cocaethylene, a derivative formed from cocaine and ethanol in the body, on the mitogen-stimulated production of cytokines by splenocytes. C57B1 mice were injected twice daily with 20 mg/kg cocaine or equivalent dose of cocaethylene and received a liquid Lieber-DeCarli diet containing ethanol (26% of total calories) or isocaloric amount of maltose-dextrin. After 4 weeks of treatment cocaine and cocaethylene caused a significant decrease of the spleen weight and total number of splenocytes. In splenocytes isolated from the cocaine- or cocaethylene-treated mice mitogen-stimulated production of gamma-interferon, tumor necrosis factor, and interleukin-2 was suppressed, in all cases more severely when cocaethylene was used. Thus formation of cocaethylene during simultaneous consumption of cocaine and ethanol may enhance the immunotoxicity of cocaine.