Impact of Buprenorphine Dosage on the Occurrence of Relapses in Patients with Opioid Dependence.

ABSTRACT

OBJECTIVES: Buprenorphine (BUP) is used in opioid maintenance treatment (OMT) for opioid-dependent patients. Previous real-world evidence suggests that many patients receive lower BUP dosage than recommended, with 38% of patients receiving <6 mg BUP per day. The goal of this research is to evaluate the impact of BUP dosage on the risk of relapses in the real world. METHODS: This study was based on German claims data of 4 million patients. Patients identified by International Classification of Diseases, 10th Edition F11.2 (opioid dependence) between 2011 and 2012 and at least one BUP prescription were selected for this study (n = 364) and followed up over 4 years. Patients were assigned to 6 dosage groups, with <6 mg/day serving as low dosage/reference category. The impact of dosage on the occurrence of relapses (indicated by treatment interruption of >3 months without OMT prescription or hospital admissions) was examined using multivariate logistic regression. Age, gender, comorbidities, fixed/variable dosing, and up-dosing were used as covariates. RESULTS: Results showed a protective effect of higher BUP as higher BUP dosages were significantly associated with a lower risk of relapse. Using low dosage (<6 mg/day) as the reference category, ORs were 0.40 (95% CI 0.19-0.87) at 6-<8 mg/day, 0.28 (0.15-0.56) at 8-<10 mg/day, 0.26 (0.10-0.67) at 10-<12 mg/day, 0.40 (0.18-0.92) at 12-<16 mg/day, and 0.18 (0.09-0.37) at ≥16 mg/day. No covariate showed a significant effect on the probability of relapse. CONCLUSIONS: The present study used a large German health claims dataset to confirm that higher BUP dosages are a protective factor for avoiding relapses in opioid-dependent patients, thus highlighting the importance of adequate BUP dosing in relapse prevention.