Comparing the Effect of Methadone, Buprenorphine, and Opium Tincture on QTc Interval in Addicted Patients Undergoing Maintenance Therapy
Abstract Background : Methadone, buprenorphine, and opium tincture are effective in the treatment of opioid dependency. Currently, in Iran, these three drugs are used in the maintenance therapy program of opioids. On the other word, there are concerns about the incidence of secondary torsade de point (TdP) arrhythmia caused by the prolonged drug-dependent QTc interval. This cross-sectional study has been designed to evaluate and compare the effects of these three maintenance therapies on the QTc interval. Methods : The study population included 110 patients (85% male with the mean age of 51.66±13.34) who participated in an opioid maintenance therapy program for at least 6 months. These patients were assigned to three groups of maintenance therapy with methadone (n = 50), buprenorphine (n = 30) and opium tincture (n = 30). For each patient, a 12-lead ECG was acquired and interpreted. The QT interval was corrected based on the QTc = QT + 1/75 (heart rate - 60) formula. Results : The mean QTc interval was 408.51 ± 25.88 msec in the maintenance therapy group with methadone, 405.58 ± 20.8 msec with buprenorphine and 406.31 ± 16.9 with opium tincture. There was no significant difference between the three groups (P = 0.83). There was only one case with QTc more than 500 msec (511.25 msec) in the maintenance therapy group with methadone. Conclusions : Methadone, buprenorphine and opium tincture are safe drugs in terms of prolonging the QTc interval and are suitable candidates for maintenance therapy of opioid.