Outpatient initiation and rotation to methadone in palliative care patients with cancer-related pain

Abstract

9587 Background: Methadone is an effective and very inexpensive opioid for cancer pain treatment. It has been reported as difficult to use in the outpatient setting due to its variable relative potency and long half-life. The purpose of this study was to determine the outcome of methadone initiation for cancer pain treatment in our palliative care outpatient center. Methods: 189 consecutive patients were either initiated or rotated to methadone in the outpatient center by our palliative care physicians after April 2003. We reviewed their medical charts for demographics and clinical characteristics, symptoms, opioid side effects, and toxicities at baseline, first (F1), and second follow up (F2). Failure was defined as methadone discontinuation by the palliative care physician or patient’s hospitalization for uncontrolled pain or methadone related side effects. Results: 100 (53%) patients were female, 138 (73%) were white, 182 (96%) had solid cancers, 80 (42%) had neuropathic pain. Median age was 60 years. 100 (53%) were initiated on methadone and 89 (47%) patients were rotated from other strong opioid to methadone. The main reason for rotation was pain (65 patients, 47%). Median (range) pain scores (Edmonton Symptom Assessment System 0–10, ESAS) were 6 (0–10), 4 (0–10), and 3 (0–10) at baseline, F1, and F2, respectively (p<0.0001). Median (range) nausea scores (ESAS) were 1 (0–10), 0 (0–8), and 0 (0–8) at baseline, F1, and F2, respectively (p=0.04). Median drowsiness scores (ESAS) were 2 (0–10), 3 (0- 10), and 2 (0–10) at baseline, F1, and F2, respectively (p=ns). The success rates for methadone initiation and rotation to methadone were 82/89 (92%) and 84/100 (84%), respectively. Median methadone dose was 10mg/day at F1 and 15mg/day at F2. Constipation improved significantly (p=0.004) with the rotation to methadone. Side effects such as sedation, hallucinations, myoclonus, and delirium showed a trend towards improvement after initiation or rotation to methadone. Conclusions: Outpatient methadone initiation and rotation for cancer pain treatment were safe, with high success rate and low side effect profile. No significant financial relationships to disclose.