Development and Evaluation of a Methadone Protocol for Severe Chronic Pain Management

The starting methadone dose for naïve-opioid patients was 2.5-5 mg every 8-12 hours. In patients who required opioid rotation, the conversion ratios, morphine:methadone, were 4:1, 8:1, and 12:1 for patients receiving less than 90 mg of morphine, receiving 90-300 mg of morphine, and receiving more than 300 mg of morphine , respectively. A fixed dose ratio of 1:20 was applied for changing from transdermal fentanyl to oral methadone. Then, the daily calculated methadone dose was divided into 8-12 hourly dosing. Calculated rescue dose was estimated to be 10-15% of total daily dose of methadone which there was switched to be morphine syrup in the ratio of 1:4.