Antemortem and postmortem methamphetamine blood concentrations: three case reports.

We compare antemortem whole-blood to postmortem peripheral blood concentrations of methamphetamine and its metabolite amphetamine in three medical examiner cases. Antemortem specimens, initially screened positive for methamphetamine by ELISA, were subsequently confirmed, together with the postmortem specimens, by GC-MS analysis following solid-phase extraction. Methamphetamine peripheral blood to antemortem blood ratios averaged 1.51 (± 0.049; n = 3) and amphetamine peripheral blood to antemortem blood ratios averaged 1.50 (n = 2). These data show that postmortem redistribution occurs for both methamphetamine and amphetamine, revealing that postmortem blood concentrations are ∼1.5 times greater than antemortem concentrations. Furthermore, as both methamphetamine and amphetamine have previously been shown to have liver/peripheral blood (L/P) ratios of 5-8, it can be proposed that drugs displaying L/P ratios ranging from 5 to 10 may exhibit postmortem concentrations up to twice those concentrations circulating in blood before death.