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 and hepatitis C was admitted to our hospital with TdP. The patient had collapsed and was found on the ground. Two days earlier, he had used methadone, intravenous heroine, and cocaine. The patient had complained of dizziness and syncope before. There was no family history of SCD. Auscultation of the heart did not reveal murmurs. Further physical examination showed no abnormalities besides a haematoma in the right flank. During examination, TdP were observed on the monitor (Fig. ).\nLaboratory results showed no hypokalaemia or hypomagnesaemia. The electrocardiogram showed a prolonged corrected QT interval (QTc) of 600 ms (Fig. ). Continuous telemetry observation showed multiple episodes of TdP. Metoprolol 50 mg, twice daily, induced mild bradyarrhythmia (50 beats/min) with augmentation of the episodes of TdP. Isoprenaline was started, after which no more TdP were seen. Angiography of the coronary arteries and the left ventricle did not show any abnormalities. The patient was diagnosed with bradyarrhythmia-induced TdP with acquired LQTS resulting from methadone use. The QTc normalised within 2 weeks after discontinuation of the methadone (Fig. ). 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. Three months later, the patient was still clean. He refused implantable cardioverter defibrillator (ICD) or pacemaker implantation because of possible complications in case of a drug relapse.