Cause of Death Conundrum With Methadone Use

Deaths caused by a methadone intoxication or overdose are becoming more frequent. We report a case involving a patient who had extremely high methadone blood concentrations but whose cause of death may have been unrelated to the drug. A 51-year-old woman was found deceased in bed by her daughter. At the scene were numerous bottles of methadone, with the chronic dosage of 240 mg 3 times a day. There was no history of prior suicide attempts, there were no reports of suicidal ideation having been voiced and there was no suicide note. At autopsy, there were no pills found in the stomach. Microscopic tissue examination revealed lobar pneumonia of the right lower lobe. Postmortem lung cultures grew out Streptococcus pneumoniae. Femoral blood contained methadone, 5.7 mg/L; EDDP, 2.1 mg/L; oxycodone, 0.017 mg/L; doxylamine, 0.022 mg/L; and ethanol, 13.0 mg/dL. The postmortem methadone concentration was consistent with her known dose, plausible pharmacokinetics and conditions of discovery. Various causes of death, such as a methadone-related arrhythmia from QTc prolongation or the contribution of methadone to the development of the pneumonia, cannot be ruled out and may well have caused or contributed to death, but the pneumonia was felt to be a competent cause of death. Ultimately, the most likely cause(s) of death, is a decision left to the individual medical examiner. This case is illustrative of the growing number of similar cases facing forensic pathologists. The cause of death cannot be solely based on drug concentrations and it may not be possible to come to a conclusion as to "the" cause of death and the forensic pathologist must be content with "a" cause of death.