Methadone Associated With Initial QTc Prolongation in Chronic Pain
(HealthDay News) — For patients with chronic pain, methadone is associated with a small, but nonsignificant, initial increase in QTc, which does not persist, according to a study published in the June issue of Pain Medicine.
Samuel Grodofsky, MD, from the University of Pennsylvania in Philadelphia, and colleagues conducted a prospective cohort study in a chronic pain clinic involving 82 patients receiving methadone and 102 receiving non-methadone opioid therapy. Automated QTc calculations from 12-lead electrocardiograms were analyzed at baseline and during the subsequent six months.
The researchers found that there was no overall higher frequency of QTc >470 milliseconds in the methadone group (6% for methadone group vs. 5% for controls; P=0.722). Furthermore, the methadone group had no increase in the incidence of QTc >60 milliseconds from baseline (4 and 4% respectively; P=0.94). Patients in the methadone group exhibited an increase in QTc compared with controls in the first month after initiating methadone (5 vs. 0%; P=0.073), but the difference did not persist at three and six months.
"We believe larger scale studies to further characterize the safety profile of low-dose methadone are warranted," the authors write.