Methadone May Be Beneficial for Dialysis Patients With Pain

Clinical Pain Medicine
ISSUE: AUGUST 2013 | VOLUME: 11
Methadone May Be Beneficial for Dialysis Patients With Pain

Winnipeg, Manitoba—Should you consider methadone for your patients who are experiencing chronic pain while undergoing dialysis? The answer is maybe, according to a study of the pharmacokinetics of methadone and hydromorphone in a small number of dialysis patients.

Ryan Perlman, MD, a PGY4 anesthesiology resident at McGill University Health Centre in Montreal, presented data from a 14-patient study at the Canadian Pain Society’s 2013 annual meeting (abstract 15D). He and his co-investigators found methadone plasma levels were more stable during hemodialysis than levels of hydromorphone, and the use of methadone was not associated with more adverse events. “We don’t know for sure yet but in the future, after randomized controlled trials are completed, methadone may be the opioid of choice for dialysis patients who have chronic pain,” Dr. Perlman told Pain Medicine News.

A pain expert consulted by Pain Medicine News for a comment, Richard Boortz-Marx, MD, also had a favorable opinion about methadone.

“The longer you’re in this line of patient care, the more you realize that the older drugs they pooh-poohed have a place if used appropriately,” said Dr. Boortz-Marx, director of interventional pain medicine at Duke University in Charlotte, N.C. “I’ve used methadone as the primary pain-relieving medication in dialysis patients for probably 10 years. It isn’t dialyzed off. With many other medications, the serum levels drop drastically during dialysis and the physicians will have the patient double or triple the dose to get the serum levels up, but that seems potentially dangerous from my perspective.”

He noted there is a concern of QT interval prolongation with methadone, but physicians can minimize the p

otential for harm by good medication monitoring as well as starting with a low dose, escalating slowly and titrating to effect, and making sure patients tell other physicians they are on methadone in case the physicians write a prescription for a medication that also can affect cardiac conduction. Physicians in the United States do not require a special license to prescribe methadone for pain, Dr. Boortz-Marx added.

Dr. Perlman and his co-investigators examined the pharmacokinetics during dialysis in seven patients receiving methadone for chronic pain and seven others receiving the opioid hydromorphone. For the first two weeks of the prospective study the pain treatment was optimized, and for the next two weeks the patients underwent dialysis blood sampling to determine opioid plasma levels and systematic testing of pain levels, opioid-related adverse effects and quality of life.

The results showed the serum concentration of hydromorphone fell by 60%, whereas for methadone it fell by only about 10%. There were also significantly higher rates of clearance and extraction of hydromorphone than methadone, confirming the serum concentration results.

Methadone patients’ post-dialysis visual analog scale scores indicated they had less pain than patients taking hydromorphone, and methadone patients’ physical functioning scores on the SF-12 were higher. None of the patients had any opioid-related side effects.

Dr. Perlman and his team now hope to obtain funding for a larger randomized controlled trial to confirm these results.

—Rosemary Frei, MSc

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