Does ethanol enhance cocaine toxicity?

Results of in vitro and animal studies suggest that ethanol enhances cocaine toxicity. If so, then that this implies that in ethanol users, postmortem blood cocaine concentrations should be lower, or anatomic evidence demonstrable.

Drug concentrations and autopsy findings were compared in a sample of 72 accidental deaths, where only cocaine, cocaine metabolites, and ethanol were detected. Findings in ethanol positive (E+) and negative (E-) deaths were compared using multiple Student's t-tests and chi2 testing for categorical variables.

There were 47 E-decedents and 24E+. Mean ages were similar (40.2 +/- 8.7 and 37.5 +/- 11.1 years respectively). Mean E was 0.113 (range 0.030-0.350 g/dL), and less than 0.080 g/dL in 50% of the cases. Concentrations of C and BE were not significantly different in E- and E+ groups (C = 1.40 +/- 3.6 mg/L, and 0.76 +/- 1.93 mg/L respectively, BE = 3.04 +/- 5.36 mg/L and BE 2.09 +/- 3.77 mg/L, P = 0.4621 and 0.4520). Organ weights were pathologically increased in both groups, but not significantly different. Body Mass Index (BMI) was less (23.9 vs 25.5), and heart weight was greater (449 vs 407 g) than predicted. Over half the decedents had demonstrable heart disease, and 11% died of brain haemorrhage, though the rate for both disorders was similar in each group.

In two-thirds of the cocaine-related deaths studied, no ethanol was detected. When ethanol was present, no differences between the two groups were identified. The findings suggest that acute cocaine toxicity is not enhanced by ethanol cocaine interactions. However, ethanol concentrations were generally low, and it is possible that increased toxicity is apparent when much larger quantities of alcohol have been consumed.