Methadone Toxicity Fatalities: A Review of Medical Examiner Cases in a Large Metropolitan Area*

Abstract

Over the past several years, Medical Examiners in Kentucky and around the nation have observed a dramatic rise in drug intoxication deaths involving the prescription medication methadone. This documented rise in methadone-related deaths requires a better understanding of methadone's pathophysiology and the ways it contributes to significantly increase morbidity and mortality. This study reviews 176 fatalities ascribed to methadone toxicity by the Office of the Chief Medical Examiner in Kentucky between 2000 and 2004. Postmortem toxicological analysis recorded a more than 10-fold increase in methadone toxicity fatalities, rising from 6 cases in 2000 to 68 cases in 2003. Of the 176 methadone-related fatalities, methadone was the only drug detected in postmortem blood and urine toxicological analyses in 11 (6.25%) cases. The mean methadone blood concentration of all 176 cases was 0.535 mg / L (0.02-4.0). The following psychoactive medications were detected: antidepressants (39.8%), benzodiazepines (32.4%), and other opioids in addition to methadone (27.8%). Cannabinoids were detected in 44 (28.4%) cases and cocaine or metabolite in 34 (21.9%) cases. Of the 95 cases with a known history of methadone use, 46 (48.4%) involved prescription by private physician. The interpretation of blood methadone concentrations alone or combined with other psychoactive drugs requires consideration of the subject's potential chronic use of and tolerance to the drug. A thorough investigation into the practices of procurement and use/abuse of methadone is essential to arrive at the proper designation of the cause of death.

Trends in methadone-related deaths in Zurich

“…We observed an increase in the number of methadone-related deaths in recent years which is consitent with the findings of many other investigators [6,9,17,18,22]. One author however found a decrease [16] -but this finding may result from only a small collective.…”

“…However, some shorter studies of five years in length or less presented data with an even larger number of victims [5,18].…”

“…Because of its long half-life, good enteral resorption and low costs it became an important substance in the treatment of opiate addiction [2,16,18,22]. This measure successfully helped to reduce mortality, criminal behaviour and the spreading of disease transmitted through intravenous drug use [18,19].…”

“…Maintenance programmes in Switzerland were made legal in 1975 and have always been using only the racemic mixture (dl-methadone). Easy access to substitution programmes was implemented in the canton of Zurich in 1991 [4,15,18].…”

“…The opioid methadone was initially synthesized by the chemists Max Bockemühl and Gustav Erhart in 1939 and first used as a highly potent analgesic [18]. Because of its long half-life, good enteral resorption and low costs it became an important substance in the treatment of opiate addiction [2,16,18,22].…”