Experience of methadone therapy in 100 consecutive chronic pain patients in a multidisciplinary pain center

Abstract

Objective: The objective of the study was to describe the experience of methadone use in 100 consecutive chronic pain patients managed in a single multidisciplinary center.

Design: A chart review of chronic pain patients on methadone therapy initiated at the Wasser Pain Management Center from January 2001 to June 2004. SETTING, PATIENTS, AND INTERVENTION: Outpatients receiving methadone for chronic pain management in a tertiary multidisciplinary pain center.

Outcome measure: Effects on pain relief and function, conversion ratio from other opioids, side effects, and disposition were reviewed.

Results: Charts of 100 methadone patients (age 45 +/- 11 years old; M/F: 3/7; duration of pain 129 +/- 110 months) managed by five physicians and one nurse were reviewed. The main reason for the initiation of methadone therapy was opioid rotation (72%). The average oral morphine equivalent dose was 77 mg/day before methadone therapy, and the methadone dose after initial stabilization was 42 mg with no consistent conversion ratio observed. The mean duration of methadone therapy was 11 months. Most of the patients (91%) were taking concomitant adjuvant analgesics or psychotropic agents, mostly antidepressants and anticonvulsants. The average Numeric Verbal Rating Score before and after methadone treatment was 7.2 +/- 1.7 and 5.2 +/- 2.5 (P < 0.0001). Thirty-five patients discontinued their methadone treatment mainly because of side effects, ineffectiveness, or both.

Conclusion: From our experience, methadone is an effective alternative to conventional opioids for chronic pain management when used by experienced clinicians in a setting that allows for close monitoring and careful dose initiation and adjustment.