[Possible influence of psychotropic drugs detected in blood when determining the cause of death in medicolegal autopsy cases in the Tokyo Medical Examiner's Office].

We reviewed the records of 118 medicolegal autopsy cases, in which psychotropic drugs were detected in blood, in the Tokyo Medical Examiner's Office in 1997, to explore how the drug levels were considered in determining the cause of death. Names and doses of the drugs were clear in 70 of 118 cases, and in most cases of the 70 cases, multiple drugs (up to 13 drugs) were prescribed to a person. It was also evident that 75 of the 118 cases had demonstrated psychosis for several months to 38 years prior to death. No information concerning prescriptions or history of psychosis could be obtained in the other cases. The causes of death in these 118 cases were as follows: deaths from specific diseases, 30 cases (25.4%); deaths from extrinsic factors excluding drug intoxication, 22 cases (18.6%); suicide related to drug intoxication, 31 cases (26.3%); deaths from extrinsic factors related to drug intoxication suggestive of suicide, but not confirmed, 19 cases (16.1%); non-suicide, including probable drug intoxication, 13 cases (11.0%); and deaths from malignant syndrome, 3 cases (2.5%). There were cases diagnosed as death from specific diseases based on morphological findings, though drug concentrations in blood were at a toxic or even lethal level. In some cases, drug intoxication was suspected, but drug levels in their blood were at a therapeutic level and there were no identifiable morphological changes directly associated with deaths, resulting in a cause of death other than drug intoxication being indicated. Thus, drug levels detected in the cadaver's blood are not always useful for determining the cause of death. This might be due to poor information on interactions between drugs (including alcohol), pathological changes or genetic variability of drug metabolism and excretion, and so on. Thus, further studies of these aspects are needed in order to make information on drugs detected in the cadaver more useful for determination of cause of death.