New methadone safety clinical practice guideline released

New guidelines for prescribing methadone for opioid addiction and pain management offer advice for primary care and specialty providers about safety and electrocardiogram monitoring to identify patients at high risk for cardiac problems.

The American Pain Society convened an expert panel that reviewed more than 3,700 scientific abstracts under the direction of the Oregon Evidence-based Practice Center to develop the new methadone safety guideline, which appeared online at The Journal of Pain.

According to the guideline, clinicians should perform an individualized medical and behavioral risk evaluation to assess risks and benefits of methadone (strong recommendation, low-quality evidence). Careful patient selection for methadone is essential and should be based on a thorough history, review of medical records, and physical examination. Assessment results can be used to stratify patients based on their risk for substance abuse, drug interactions, arrhythmias.

The guidelines recommend educating and counseling patients before prescribing methadone about the indications for treatment and goals of therapy, availability of alternative therapies, and specific plans for monitoring therapy, adjusting doses, and dealing with potential adverse effects (strong recommendation, low-quality evidence).

Clinicians should do an electrocardiogram (ECG) before starting methadone in patients with risk factors for QTc interval prolongation, and consider doing an ECG before starting methadone in patients not known to be at higher risk. Buprenorphine is an option for patients being treated for opioid addiction who have risk factors for prolonged QTc intervals.

Clinicians should begin methadone at low doses based on the indication for treatment and prior opioid exposure status, titrate doses slowly, and monitor patients for sedation (strong recommendation, moderate-quality evidence). Methadone should be withheld if there is evidence of sedation.

When used to treat opioid addiction, clinicians should start methadone at no more than 30 to 40 mg once daily, titrated by no more than 10 mg/d and no more frequently than every 3 to 4 days. When used to treat chronic pain in adults on relatively low doses of other opioids (such as <40–60 mg/d of morphine or equivalent), clinicians should start methadone at 2.5 mg tid, with initial dose increases of no more than 5 mg/d every 5 to 7 days. When used to treat chronic pain and switching to methadone from higher doses of another opioid, clinicians can start methadone therapy at a dose 75% to 90% less than the calculated equianalgesic dose and at no higher than 30 to 40 mg/d, with initial dose increases of no more than 10 mg/d every 5 to 7 days.

Clinicians can consider those patients previously prescribed methadone, but who have not currently taken opioids for 1 to 2 weeks, as opioid-naïve when restarting methadone (strong recommendation, low-quality evidence).

Clinicians should conduct urine drug screens before starting methadone and at regular intervals in patients prescribed methadone for opioid addiction (strong recommendation, low-quality evidence). Also, patients prescribed methadone for chronic pain who have risk factors for drug abuse should undergo urine drug testing before starting methadone and at regular intervals thereafter. Clinicians can consider urine drug testing in all patients regardless of assessed risk status (strong recommendation, low-quality evidence).