Concerns About Consensus Guidelines for QTc Interval Screening in Methadone Treatment FREE

TO THE EDITOR:

We read with great consternation the clinical guidelines by Krantz and colleagues (1) advocating rate-corrected QT interval (QTc) screening for methadone treatment. In our opinion, not only are the recommendations short-sighted and irresponsible, but they are also detrimental to society at large.

We foresee multidimensional problems with these guidelines. First, Krantz and colleagues do not appreciate that, for most opioid users (both former substance abusers and pain patients), methadone represents a last-resort treatment. Therefore, even if a prolonged QT interval is found, the likelihood that an equally effective alternative treatment could be implemented is remote (2).

Second, compared with the other potentially catastrophic risks associated with methadone, the chance of a fatal arrhythmia is minimal. The side effects and potential complications of opioid use in general far outweigh the marginally increased risk entailed by methadone use (3 - 4). Not only methadone, but also oxycodone, has been associated with the surrogate outcome measure of a prolonged QT interval, suggesting that the full-fledged earthquake (that is, “recommendations” that in essence become restrictive practice mandates because of the litigious nature of our society) may be just over the horizon (5). Should we then perform serial ECG on every patient who initiates opioid therapy, including on emergency department visits and ambulatory surgical procedures? Or, because the sensitivity of 1 ECG screening is quite low, maybe we need to increase the surveillance interval to every month?

Finally, the guidelines do not address a possible relationship between changes observed on ECG and dose, dosing interval, and treatment duration. Does this imply that a patient taking methadone, 5 mg twice daily, should be treated identically to a patient taking 100 mg three times daily? If so, this would be antithetical to everything we'e learned about drug-related toxicity.

We do agree that the surge in methadone use has resulted in a corresponding increase in drug-related deaths. But we have no way of knowing how many of these are due to arrhythmias, misuse, or lack of physician education. We do not live in a society in which time and resources are unlimited, people are altruistic, and cost is irrelevant. Besides cardiologists, the only people likely to benefit from the published recommendations are ECG manufacturers and trial lawyers.

Steven P. Cohen, MD

Johns Hopkins School of Medicine

Baltimore, MD 21205

Jianren Mao, MD, PhD

Massachusetts General Hospital, Harvard Medical School

Boston, MA 02114