Cocaine-related torsade de pointes in a methadone maintenance patient.
A patient maintained on methadone for opioid-dependency developed recurrent syncope. Episodes occurred within hours after using cocaine, and were initially presumed secondary to seizure disorder. However, the patient subsequently suffered a cardiac arrest, and polymorphic ventricular tachycardia (torsade de pointes) was documented. Other than cocaine and methadone the patient was receiving no additional agents known to prolong the QT interval. Low serum methadone concentrations and marked reversible left ventricular systolic dysfunction were noted during the hospitalization. These findings, in conjunction with a history of torsade de pointes temporally related to cocaine abuse, suggest that cocaine was a major precipitant of arrhythmia. Recent experimental studies have shown that cocaine and methadone prolong the QT interval through the same mechanism. We examine the effects of cocaine and methadone on cardiac conduction in the context of the opioid-dependent population.
Krantz
Mori J
MJ
Department of Internal Medicine, Denver Health Medical Center, Denver, CO 80204-4507, USA. Mkrantz@dhha.org
Rowan
Shane B
SB
Mehler
Philip S
PS
D003042:Cocaine / Q000009:adverse effects*; D018765:Dopamine Uptake Inhibitors / Q000009:adverse effects*; D004347:Drug Interactions; D005260:Female; D006323:Heart Arrest / Q000209:etiology; D006556:Heroin Dependence / Q000534:rehabilitation; D006801:Humans; D008691:Methadone / Q000009:adverse effects* / Q000627:therapeutic use*; D008875:Middle Aged; D009294:Narcotics / Q000009:adverse effects* / Q000627:therapeutic use*; D016171:Torsades de Pointes / Q000139:chemically induced*; D016277:Ventricular Function, Left
D018765:Dopamine Uptake Inhibitors; D009294:Narcotics; D003042:Cocaine; D008691:Methadone