Objectives: To compare the efficacy of a low-dose methadone tapering schedule to a high-dose methadone tapering schedule in pediatric intensive care unit patients exposed to infusions of fentanyl, with or without infusions of midazolam, for ≥ 5 days.
Design: Prospective, double-blind, randomized trial.
Setting: Pediatric intensive care unit in a tertiary care children's hospital.
Patients: Seventy-eight patients, 74 of whom had been receiving infusions of both fentanyl and midazolam, were randomized. Forty-one patients were randomized to the low-dose methadone group and 37 were randomized to the high-dose methadone group. Sixty patients successfully completed the trial, 34 were in the low-dose methadone group, and 26 were in the high-dose methadone group.
Interventions: Patients were randomized to receive methadone either at a starting dose of 0.1 mg/kg/dose (low-dose methadone group) or at a starting dose based on both the patient's weight and the most recent fentanyl infusion rate (high-dose methadone group). In each group, methadone was administered every 6 hrs for the first 24 hrs and then every 12 hrs for the second 24 hrs. The methadone was then decreased to once daily and tapered off over the next 10 days. Patients were monitored for withdrawal symptoms using the Modified Narcotic Withdrawal Score.
Measurements and main results: The percentage of patients who successfully completed the 10-day methadone taper was the same in the low-dose methadone group as in the high-dose methadone group (56% vs. 62%; p = .79). Patients that failed to complete the assigned methadone taper had a greater total fentanyl dose and longer pediatric intensive care unit length of stay compared to patients who completed the assigned methadone taper.
Conclusions: Patients who received infusions of fentanyl for at least 5 days were just as likely to complete a low-dose methadone taper as a high-dose methadone taper. Because of the risks of both withdrawal and oversedation with any fixed methadone schedule, the methadone dose must be adjusted according to each patient's response.