Methadone-Buprenorphine Transfers Using Low Dosing of Buprenorphine: An Open-label, Nonrandomized Clinical Trial

AimsTo compare a low-dosing protocol to standard practice for methadone-buprenorphine transfers.MethodsWe undertook a nonrandomized open-label clinical trial across 8 sites from NSW, Australia. Participants prescribed methadone wishing to transfer to buprenorphine could either choose or be randomized to a low-dose transfer or standard care transfer as per NSW health guidelines. The low-dose protocol started at 0.2 mg BD and increased to 16 mg on day 6, with flexible dosing thereafter. The primary outcome was continuation of buprenorphine 1 week post-transfer. Binary logistic regression was used to access the primary outcome with demographic differences between the groups included as covariates.ResultsThere were 117 participants who commenced the study, 101 in the low-dose arm and 16 in standard care. Mean methadone dose was 82 mg in the low-dose arm and 46 mg in standard care. The primary outcome was met by 81 participants in the low-dose arm (80%) and 13 participants in standard care (81%). There was no significant between-arm difference in the odds of the primary outcome (OR = 2.22; 95% CI: 0.45-10.91; P = 0.327). Four participants (4%) in the low-dose arm experienced precipitated withdrawal against 1 (6%) in standard care. Higher methadone dose decreased the odds of successful transfer by 20% (OR = 0.8 per 10 mg methadone; 95% CI: 0.7-0.99; P = 0.04). Withdrawal scores between the 2 arms were similar.ConclusionsWe were unable to detect a difference between low dosing and standard care for methadone to buprenorphine transfers. Increasing methadone dose was a predictor of success; setting (ambulatory or inpatient) was not.