Methadone Linked to Sudden Cardiac Death
Researchers at Oregon Health & Science University have concluded that methadone is a possible cause of sudden cardiac death. The study determined that sudden cardiac death could be caused by methadone even when it was taken at therapeutic levels for relief of chronic pain or drug addiction withdrawal. The study's findings were based on an evaluation of all sudden cardiac deaths in the greater Portland, Oregon metropolitan area between 2002 and 2006 where detailed autopsies were performed.
The analysis was based on a comparison of two case groups. One group consisted of 22 sudden cardiac deaths in which toxicology screens turned up 1 mg or less of methadone which is defined as therapeutic level. The cases were then compared to a second group of 106 cases where no evidence of methadone was found. In the first case group, 17 of the 22 subjects had no significant cardiac abnormalities. On the other hand, 60% of the case group where no methadone is present had identifiable evidence of cardiac disease or structural abnormalities. "The unexpectedly high proportion of otherwise unexplained sudden deaths in the therapeutic methadone group points to a significant contribution of this drug towards the occurrence of sudden cardiac death among these patients" said Sumeet Chugh, M.D. lead investigator, Director of OHSU's Cardiac Arrhythmia Center, and Associate Professor of Cardiovascular Medicine in the OHSU School of Medicine. Individual case reports have linked methadone to a rare ventricular arrhythmia, known as torsade de pointes, which can degenerate into ventricular fibrillation leading to sudden death in the absence of medical intervention.
The researchers have proposed that a large prospective evaluation of methadone therapy be undertaken since a sizable and growing number of people are utilizing methadone for both pain management and drug addiction.
