Methadone safe in cancer patients - minor QT problems went away after 4-8 weeks methadone!
Posted: November 16, 2009 20:28
The Effect of Oral Methadone on the QTc Interval in Advanced Cancer Patients: A Prospective Pilot Study. Reddy S, Hui D, El Osta B, de la Cruz M, Walker M, Palmer JL, Bruera E. Journal of Palliative Medicine, October 13, 2009 E-pub ahead.
Dear Colleagues,
These authors have done a great service by following serial ECGs prospectively on 100 patients who were being considered for methadone treatment for advanced cancer pain. ECG was ordered at baseline, 2, 4 and 8 weeks. Due to altered medication, hospice transfers, community discharges and one death (non-cardiac) in this palliative patient population the follow up results were available for 64, 41, and 27 patients at 2, 4 and 8 weeks.
Perhaps the most interesting and unexpected findings of this study were that even before starting the medication, over a quarter of patients (28%) had QT prolongation (>430 ms in males; >450 ms in females) and this dropped. The proportion of subjects was *lower* at each of the follow-up periods with only 8-11% of patients having QT prolongation.
At two weeks 11 patients (17%) had QTc>10% above baseline. However, by 4 and 8 weeks this had dropped to one single patient (3%). There was only one ECG in one single patient where QTc increased beyond 500ms (1.6%). This was asymptomatic and not associated with any tachycardia episode. Furthermore, that patient’s prolonged QT resolved spontaneously in subsequent ECG tracings. The authors express their surprise at these unexpected findings which they ascribed partly to the high baseline occurrence of QT prolongation and/or possibly a reduction in other drugs prescribed or improvements in electrolyte disturbances.
The doses of methadone were relatively low compared to the dose levels used for addiction (median at 2 weeks 23mg daily and maximum was 90mg daily).
The authors conclude: “clinically significant QTc prolongation rarely occurred … our preliminary findings are encouraging. … we believe that methadone should be prescribed without reservations … . For patients with significant risk factors … monitoring with ECGs at baseline and at subsequent intervals may be reasonable.”
This should give doctors and patients confidence that methadone is still a safe and effective analgesic and that concerns regarding cardiac side effects may have been exaggerated out of keeping with the literature. When I contacted the study’s author I was told that they had seen no cases of torsade tachycardia in relation to methadone treatment at the MD Anderson Cancer Center to date.
Comments by Andrew Byrne ..
Dear Colleagues,
These authors have done a great service by following serial ECGs prospectively on 100 patients who were being considered for methadone treatment for advanced cancer pain. ECG was ordered at baseline, 2, 4 and 8 weeks. Due to altered medication, hospice transfers, community discharges and one death (non-cardiac) in this palliative patient population the follow up results were available for 64, 41, and 27 patients at 2, 4 and 8 weeks.
Perhaps the most interesting and unexpected findings of this study were that even before starting the medication, over a quarter of patients (28%) had QT prolongation (>430 ms in males; >450 ms in females) and this dropped. The proportion of subjects was *lower* at each of the follow-up periods with only 8-11% of patients having QT prolongation.
At two weeks 11 patients (17%) had QTc>10% above baseline. However, by 4 and 8 weeks this had dropped to one single patient (3%). There was only one ECG in one single patient where QTc increased beyond 500ms (1.6%). This was asymptomatic and not associated with any tachycardia episode. Furthermore, that patient’s prolonged QT resolved spontaneously in subsequent ECG tracings. The authors express their surprise at these unexpected findings which they ascribed partly to the high baseline occurrence of QT prolongation and/or possibly a reduction in other drugs prescribed or improvements in electrolyte disturbances.
The doses of methadone were relatively low compared to the dose levels used for addiction (median at 2 weeks 23mg daily and maximum was 90mg daily).
The authors conclude: “clinically significant QTc prolongation rarely occurred … our preliminary findings are encouraging. … we believe that methadone should be prescribed without reservations … . For patients with significant risk factors … monitoring with ECGs at baseline and at subsequent intervals may be reasonable.”
This should give doctors and patients confidence that methadone is still a safe and effective analgesic and that concerns regarding cardiac side effects may have been exaggerated out of keeping with the literature. When I contacted the study’s author I was told that they had seen no cases of torsade tachycardia in relation to methadone treatment at the MD Anderson Cancer Center to date.
Comments by Andrew Byrne ..
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