Methadone Inpatient and Discharge Prescribing Patterns for Pain at an Academic Health System

Abstract

Background: Methadone is effective for the treatment of chronic pain, but its unique pharmacology requires additional considerations with dosing and monitoring.

Objective: The study objective was to evaluate methadone prescribing for pain and subsequent monitoring.

Methods: This retrospective chart review at a single center reviewed patients who received methadone over a two-year period.

Results: Of the 100 patients, most were noncancer cases (60%) with unspecified pain (50%). The majority of methadone treatments were initiated by medicine service (37%), followed by burn service (27%), and trauma (10%). Forty-two percent of the patients were being followed by the palliative care team, primarily for the medicine patients (80%). Patients on the burn service had significantly higher oral morphine equivalent (χ² = 10.6, p = 0.01) and longest length of stay (χ² = 37.9, p = 0.0001). Patients on medicine service were significantly more likely to have an outpatient discharge plan for methadone starts in the hospital (odds ratio = 3.7, confidence interval: 1.4, 9.7). Only 45% of patients had an electrocardiogram (EKG) checked seven days before methadone start and 37% of those have a measured corrected QT (QTc) of greater than 450 milliseconds. Electrolytes (potassium and magnesium) were not consistently checked and, of those that were evaluated, 15-20% were abnormal. There was an average of 2.6 severe or major drug interactions per patient related to methadone, with the most common being related to concomitant sedatives and other medications that prolonged the QTc.

Conclusions: Prescribing guidelines for methadone would provide a consistent approach for all practitioners involved in using methadone safely and effectively for chronic pain.

Keywords: burn; chronic pain; methadone; mixture of nociceptive and neuropathic pain; pain.