Buprenorphine implants for treatment of opioid dependence. A randomized controlled trial (2010)

Context: Limitations of existing pharmacological treatments for opioid dependence include low adherence, medication diversion, and emergence of withdrawal symptoms.
Objective: To determine the efficacy of buprenorphine implants that provide a low, steady level of buprenorphine over 6 months for the treatment of opioid dependence.
Design, Setting, and Participants: A randomized, placebo-controlled, 6-month trial conducted at 18 sites in the United States between April 2007 and June 2008. One hundred sixty-three adults, aged 18 to 65 years, diagnosed with opioid dependence. One hundred eight were randomized to receive buprenorphine implants and 55 to receive placebo implants.
Intervention: After induction with sublingual buprenorphine-naloxone tablets, patients received either 4 buprenorphine implants (80 mg per implant) or 4 placebo implants. A fifth implant was available if a threshold for rescue use of sublingual buprenorphine-naloxone treatment was exceeded. Standardized individual drug counseling was provided to all patients.
Main Outcome Measure: The percentage of urine samples negative for illicit opioids for weeks 1 through 16 and for weeks 17 through 24.
Results: The buprenorphine implant group had significantly more urine samples negative for illicit opioids during weeks 1 through 16 (P = .04). Patients with buprenorphine implants had a mean percentage of urine samples that tested negative for illicit opioids across weeks 1 through 16 of 40.4% (95% confidence interval [CI], 34.2%-46.7%) and a median of 40.7%; whereas those in the placebo group had a mean of 28.3% (95% CI, 20.3%-36.3%) and a median of 20.8%. A total of 71 of 108 patients (65.7%) who received buprenorphine implants completed the study vs 17 of 55 (30.9%) who received placebo implants (P < .001). Those who received buprenorphine implants also had fewer clinician-rated (P <.001) and patient-rated (P = .004) withdrawal symptoms, had lower patient ratings of craving (P <.001), and experienced a greater change on clinician global ratings of severity of opioid dependence (P<.001) and on the clinician global ratings of improvement (P < .001) than those who received placebo implants. Minor implant site reactions were the most common adverse events: 61 patients (56.5%) in the buprenorphine group and 29 (52.7%) in the placebo group.
Conclusion: Among persons with opioid dependence, the use of buprenorphine implants compared with placebo resulted in less opioid use over 16 weeks as assessed by urine samples. [Author's abstract]