Literature Reviews
Methadone as the Initial Long-Acting Opioid In Children With Advanced Cancer
Madden K, Mills S, Dibaj S, et al;. Journal of Palliative Medicine 2018;21(9):1317-21
Pain is a common symptom in advanced pediatric cancer. Although methadone is a long-acting drug allowing easy titration due to its availability as a liquid there is only limited information on its use in pediatric oncology. The study aimed to examine the efficacy and safety of methadone as the first long-acting opioid for uncontrolled pain in pediatric cancer patients who are opioid-naïve or just receiving short-acting opioids. Secondary objectives were the effect on sleep, fatigue, and psychological symptoms assessed by patient-reported outcome (PRO) measures.
Methods
This was a retrospective study in pediatric patients with advanced cancer in a tertiary cancer center. All patients seen by a pediatric hospice and palliative care specialist. Methadone was initiated at 0.1mg/kg po q 12 hours. Parents/guardians and children (if >6 years of age) completed the Pediatric Symptom Assessment System (PSAS), a 5-point Likert-type scale, based on the Edmonton Symptom Assessment System, the Memorial Symptom Assessment Scale (MSAS) and PediQUEST PQ-MSAS PRO tools.
Results
During the 27-month study period 52/62 (84%) patients received methadone when initiating long-acting opioid therapy. The majority of them was male (58%), white (54%), had solid tumors (69%), had isolated nociceptive (48%) or nociceptive and neuropathic (50%) pain, and was not opioid-naïve (96%). At a median follow-up of 17 days (F1) 10/47 (21%) had required an increase and 4/47 (9%) a decrease in dose. At F2 (median 55 days) 23/29 (79%) remained on unchanged doses. Five patients died of disease progression before F2. No prolonged QTc was seen in incidental ECG’s obtained in 38/47 patients during the study period. Pain and insomnia improved between baseline and F1 and F2, fatigue between baseline and F2 as reported by patient and parents. Psychological symptoms did not change. Agreement between parents and children was moderate for pain, fair for sadness and poor for other symptoms.
Conclusion
Methadone was effective in decreasing pain and insomnia in children with advanced cancer. Most patients did not need changes in their initial dose. Limitations of the study include retrospective nature and single tertiary cancer center location. (Comment: the assessment tool, though based on validated measures, was not validated itself; this study was too small to draw any conclusions on safety).
