Buprenorphine as a safe alternative to methadone in a patient with acquired long QT syndrome: a case report

A 52-year-old man with a medical history of intravenous drug abuse was admitted to our hospital with syncope due to torsades de pointes (TdP). Two days earlier, he had used methadone. The electrocardiogram showed a prolonged corrected QT interval (QTc) of 600 ms. Continuous telemetry observation showed multiple episodes of TdP. The patient was diagnosed with bradyarrhythmia-induced TdP with acquired long QT syndrome resulting from methadone use. The QTc normalised within 2 weeks after discontinuation of the methadone. In this case of a patient with opioid dependency, there is a reasonable risk of repeated methadone use. Therefore, implantable cardioverter defibrillator or pacemaker implantation is justified but risky because of possible infections when using intravenous drugs. Given the high mortality rates seen in untreated illicit opioid users, this patient needs an alternative pharmacological treatment. Buprenorphine is an opiate-receptor agonist associated with less QTc prolongation. The patient was referred to a rehab clinic and treated with an oral combination of buprenorphine and naloxone (Suboxone). During this therapy, his QTc remained normal.