Methadone as the Initial Long-Acting Opioid in Children with Advanced Cancer

Background: Methadone is an attractive medication for treating children with advanced cancer with pain as it is the only long-acting opioid available as a liquid. However, it is not frequently used due to concerns about potential toxicities and side effects. Objective: Evaluate the efficacy and safety of methadone as the first long-acting opioid in children with advanced cancer. Design: Retrospective chart review of 52 consecutive patients referred to Pediatric Supportive Care for pain management started on methadone as their first long-acting opioid. Data collected at baseline, follow-up visits #1 (F1) and #2 (F2) included child and parent-reported outcomes for various physical and psychological symptoms, opioid side effects and other clinical data. Symptoms were rated on a 0 (not at all) to 4 (a lot) scale. Results: Pain (meanstandard deviation [SD]) scored by the child was 3.6 (+/- 0.6)/4 at baseline and 1.8 (+/- 1.1)/4 at F1 (p<0.0001). Compared to baseline, pain scored by the child at F2 was 1.2 (+/- 1.3)/4 (p<0.0001). Pain scored by the parent was 3.5 (+/- 0.7)/4 at baseline and 1.4 (+/- 1.3)/4 at F1 (p<0.0001). Compared to baseline, pain scored by the parent at F2 was 1.0 (+/- 1.2)/4 (p<0.0001). Thirty-three (70%) patients at F1 and 23 (79%) patients at F2 did not need a change in dose of methadone. No cardiac arrhythmias or opioid neurotoxicity was observed. Conclusions: Initiation of methadone was effective and safe as the first long-acting opioid in children with pain.