Analysis of metformin in antemortem serum and postmortem specimens by a novel HPLC method and application to an intoxication case.

A case of intoxication from the oral hypoglycemic drug metformin is presented. A number of published liquid chromatographic methods were combined to enable a simplified analysis of metformin in both antemortem and postmortem specimens. The method involved direct injection of a protein-free filtrate into the liquid chromatograph. The method was sufficiently sensitive to detect therapeutic use of metformin; no common therapeutic or abused drugs interfered with the assay. In the presented case, the hospital admission serum metformin concentration was 141 mg/L, or approximately two orders of magnitude above therapeutic concentrations. The medical examiner concluded that the cause of death in this case was metformin intoxication, and the manner of death was suicide.