RESUMO
BACKGROUND AND OBJECTIVES: Induction is a crucial period of opioid addiction treatment. This study aimed to identify buprenorphine/naloxone (BUP) induction patterns and examine their association with outcomes (opioid use, retention, and related adverse events [AEs]). METHODS: The secondary analysis of a study of opioid-dependent adults seeking treatment in eight treatment settings included 740 participants inducted on BUP with flexible dosing. RESULTS: Latent class analysis models detected six distinctive induction trajectories: bup1-started and remained on low; bup2-started low, shifted slowly to moderate; bup3-started low, shifted quickly to moderate; bup4-started high, shifted to low; bup5-started and remained on moderate; bup6-started moderate, shifted to high dose (Fig. 1). Baseline characteristics, including Clinical Opioid Withdrawal Scale (COWS), were important predictors of retention. When controlled for the baseline characteristics, bup6 participants were three times less likely to drop out the first 7 days than bup1 participants (adjusted hazard ratio (aHR) = .28, p = .03). Opioid use and AEs were similar across trajectories. Participants on ≥16 mg BUP compared to those on <16 mg at Day 28 were less likely to drop out (aHR = .013, p = .001) and less likely to have AEs during the first 28 days (aOR = .57, p = .03). DISCUSSION AND CONCLUSIONS: BUP induction dosing was guided by an objective measure of opioid withdrawal. Participants with higher baseline COWS whose BUP doses were raised more quickly were less likely to drop out in the first 7 days than those whose doses were raised slower. SCIENTIFIC SIGNIFICANCE: This study supports the use of an objective measure of opioid withdrawal (COWS) during BUP induction to improve retention early in treatment.