Suspected Methadone Toxicity: from Hospital to Autopsy Bed

High mortality rates have been reported for methadone in both adults and children. We aimed to determine the pattern of toxicity, possible underlying diseases and treatment challenges in patients referred to our centre with early diagnosis of methadone toxicity and who later died. Medical files of all methadone-poisoned patients who had been admitted to a referral centre of toxicology between March 2011 and March 2016, died during the hospital stay and sent for autopsy to Legal Medicine Organization were retrospectively evaluated. In a total of 94 patients, autopsy findings and laboratory evaluations showed that cause of death was pure methadone toxicity in 57 (60.6%). Other causes of death were ischaemic heart disease in ten, co-ingestions (toxicities including methadone) in eight, brain haemorrhage, multi-organ failure and pneumosepsis (each in four), meningitis/encephalitis in three and head trauma and other toxicities (other than methadone but including an opioid, each in two) patients. Time of cardiopulmonary arrest was significantly different between those with pure methadone toxicity and those who died due to other causes (p = 0.01). Patients who had died due to co-ingestions and other toxicities were younger (p = 0.029) and took more bolus doses of naloxone (p = 0.042). In methadone users, especially in older ages and those with trivial response to naloxone administration, loss of consciousness should not be strictly attributed to methadone toxicity. In such patients, thorough evaluation for other possible causes of loss of consciousness is mandatory.