The role of ethanol abuse in the etiology of heroin-related death.

Toxicology analyses and other forensic science data were used to examine the mechanisms through which ethanol increased the risk for death caused by injected street preparations of heroin. The authors studied 505 victims of fatal heroin overdose and compared subjects who had concentrations of blood ethanol greater than 1000 mg/L (n = 306) with those who had concentrations less than, or equal to 1000 mg/L (n = 199). We found significant negative correlations between concentrations of ethanol and morphine (a heroin metabolite) in blood (R2 = 0.11, P = 0.0001 for log10-transformed variables) as well as between concentrations of blood ethanol and bile morphine (R2 = 0.16, P = 0.0001 for log10 bile morphine versus blood morphine). Toxicologic evidence of infrequent heroin use was more common in decedents with blood ethanol concentrations greater than 1000 mg/L than in those with lower concentrations. Our data suggest that ethanol enhances the acute toxicity of heroin, and that ethanol use indirectly influences fatal overdose through its association with infrequent (nonaddictive) heroin use and thus with reduced tolerance to the acute toxic effects of heroin.