Optimization of Pediatric Tonsillectomy to IMprove AnaLgesia

The purpose of this study is to compare the use of short acting opioids (fentanyl/hydromorphone) with long acting opioids (methadone) for pain control following tonsillectomy surgery in children and adolescents.

This is a randomized, double-blind, parallel-group, dose-escalation investigation. Participants ("children" defined as ages 3 - \< 12 years and "adolescents" defined as ages 12 - 17 years) will be randomized 2:1 to either methadone or short-acting opioid. Surgical and anesthesia care, except for intraoperative opioid management, are not altered for study purposes. The trial will include 2 periods in 3 parallel age groups. In the first period, each age cohort will recruit 66 patients (44 methadone, 22 control). Children will be randomized to methadone 0.15 mg/kg age-ideal body weight and adolescents to 0.2 mg/kg age-ideal body weight. When an age cohort reaches 66 patients, this is the end of the first period. At that time, an unblinded interim analysis will be conducted in that cohort to determine if dose escalation to 0.2 mg/kg dose in children and the 0.25 mg/kg dose in adolescents are met. Methadone dose escalation will be based on clinically meaningful differences in need for rescue opioid in the PACU and the absence of well-defined opioid adverse events. Outcomes data will be collected in hospital and after discharge. With daily surveys for 7 days, and 3 phone calls on day 30, 3 months and 6 months after surgery.