Methadone as an analgesic for patients with chronic pain in methadone maintenance treatment programs (MMTPs).

BACKGROUND

Limited case reports have suggested a role for methadone as an analgesic for chronic pain in patients maintained on methadone for treatment of opiate addiction. Patients with HIV are disproportionately represented in this population and often have severe, debilitating chronic pain syndromes of multiple etiologies, including cancer-related pain syndromes.

OBJECTIVE

This study evaluated the safety and efficacy of initiating and maintaining additional methadone for chronic pain in HIV-positive patients with ongoing treatment for opiate addiction in methadone maintenance treatment programs (MMTPs).

METHODS

We performed a retrospective chart review of 53 HIV/AIDS patients (36 male, 1 7 female; 24 with cancer) with diverse chronic pain syndromes who were followed in an HIV Pain Clinic and were currently enrolled in an MMTP. The outcome measure was pain, assessed using a numeric rating scale (0-10). Incidence of heroin use was also measured.

RESULTS

The mean methadone dose initially prescribed for analgesia was approximately equal to 67 percent of the methadone dose used in the MMTP for addiction. Over the 12-month retrospective observation period, methadone was titrated to approximately 200 percent of the methadone maintenance dose. The mean pain score at initial visit to the Pain Clinic was 9.4 +/- 1.03. After methadone for analgesia has been administered for 1 month, the mean pain score decreased to 5.35 +/- 1.7 (p < 0.001), at 3 months, 4.8 +/- 1.3 (p < 0.001), at 6 months, 4.2 +/- 1.7 (p < 0.001), and at 12 months, 4.2 +/- 1.4 (p< 0.001). No serious adverse events or side effects were observed with methadone therapy for analgesia.

CONCLUSION

HIV/AIDS patients with chronic pain enrolled in MMTPs achieved improved analgesia with no serious side effects when additional methadone was administered for pain relief. Further controlled studies are needed to confirm our findings and to establish the safety and efficacy of methadone therapy for chronic pain in this population.