Buprenorphine in primary care: risk factors for treatment injection and implications for clinical management.

AIMS Though the introduction of office-based buprenorphine has greatly contributed to stem the HIV epidemic since 1995, concerns have been raised about the intravenous use of buprenorphine even in patients on substitution treatment. The aim of this study was to identify which factors are predictive of buprenorphine injection in patients receiving office-based buprenorphine. DESIGN AND SETTING Subazur is a survey consisting of two longitudinal assessments of 111 stabilized patients receiving office-based buprenorphine in southeastern France. MEASUREMENTS Patients were interviewed by phone at enrolment and 6 months later about social characteristics, addictive behaviors, treatment experiences, overdoses and suicide ideation or attempt. A logistic regression based on generalized estimating equations (GEE) was used to identify factors associated with buprenorphine injection at any interview. FINDINGS Among the 111 patients (32% women, mean age 38 years), 36 reported buprenorphine injection after having started treatment initiation in 40 interviews. After adjustment for time since first injection, individuals perceiving their prescribed dosage as inadequate (OR=2.6 95%CI[1.2-5.7]) and those reporting a history of suicide ideation or attempt (OR=2.7 95%CI[1.1-7.0]) had approximately a three-fold higher risk of injecting buprenorphine. CONCLUSIONS Providing adequate care for both drug dependence and psychiatric comorbidities in primary care is a major issue. Like heroin use during methadone treatment, buprenorphine injection should be regarded more as a response to inadequate care than simply as a "misuse". A re-assessment of the treatment efficacy through a possible dosage increase or a switch to methadone could potentially reduce diversion and assure sustained adherence to OST.