Lack of predictable site-dependent differences and time-dependent changes in postmortem concentrations of cocaine,...

This study evaluated the stability of cocaine, benzoylecgonine, and cocaethylene in postmortem fluids in cases of cocaine-related death. Femoral and ventricular blood and cisternal cerebrospinal fluid were collected soon after death and again at the time of autopsy. In addition, iliac blood was collected at autopsy. There were no consistent patterns of site-specific differences for any of the analytes, and the central compartment showed both higher and lower concentrations than the peripheral. There was no consistent pattern of direction or magnitude of change in the concentrations with respect to time for any of the analytes. This is consistent with anecdotal reports from other workers and is believed to be a result of competing processes of tissue release and chemical and enzymatic degradation of the analytes. Postmortem cocaine and metabolite concentrations in blood are not necessarily reflective of the perimortem concentrations and should not be the primary consideration in determining the cause of death in suspected cocaine-related deaths.