Buprenorphine implants work as well if not better than sublingual buprenorphine as maintenance treatment of opioid dependence, according to results of a randomized controlled trial released today.
"This is presumably the first head-to-head safety and efficacy trial of buprenorphine implants and daily sublingual buprenorphine on long-term remission opioid use disorder in patients who were previously stabilized on 8 mg or less of sublingual buprenorphine," Richard N. Rosenthal, MD, medical director of addiction psychiatry, Mount Sinai Behavioral Health System, and professor of psychiatry, Icahn School of Medicine at Mount Sinai in New York City, told Medscape Medical News.
The buprenorphine implants proved noninferior to sublingual buprenorphine in the main outcome measure, which was maintaining abstinence from illicit opioids in at least 4 or the 6 study months. In addition, more patients in the implant group maintained abstinence over the full 6-month study compared with the sublingual treatment group, "a significant effect with a low number needed to treat (7.25) against the active base intervention, sublingual buprenorphine," Dr Rosenthal noted.
The study was published online July 19 in JAMA.
Better Results, Less Risk
The trial included 177 opioid-dependent adults with stable abstinence (mean age, 39 years; 40.9% women). They were randomly allocated to sublingual buprenorphine with four placebo implants (n = 90) or four buprenorphine implants with sublingual placebo (n = 87).
According to the researchers, 81 of 84 (96.4%) patients in the buprenorphine implant group and 78 of 89 (87.6%) of patients receiving sublingual buprenorphine responded to treatment, an 8.8% difference, meeting criteria for noninferiority (P < .001).
Over 6 months, 72 of 84 (85.7%) of those treated with buprenorphine implants maintained opioid abstinence, compared with 64 of 89 patients (71.9%) receiving sublingual buprenorphine (hazard ratio, 13.8; 95% confidence interval, 0.018 - 0.258; P = .03).
Non-implant-related and implant-related adverse events occurred in 48.3% and 23% of the buprenorphine implant group and in 52.8% and 13.5% of the sublingual buprenorphine group, respectively.
"There are some individual and public health risks with daily dosing of sublingual buprenorphine, such as missed doses and accidental pediatric exposure, as well as the risk of theft or intentional diversion," Dr Rosenthal said.
"Given that transitioning to implants was not clinically destabilizing (eg, increased craving or withdrawal symptoms) and that the implants remain in place over the active treatment period, buprenorphine implants are an opportunity to boost maintenance of abstinence while reducing the risk of diversion and adverse events," he added.
Further studies are needed in broader populations to assess the efficacy of buprenorphine implants in other settings, the investigators note.
"The current study evaluated participants who were clinically stable and referred from physicians' office-based practices," said Dr Rosenthal. "The eligible population may be larger than perceived, as 25% of buprenorphine prescriptions are for 8 mg or less. It will be important to explore treatment with buprenorphine implants in the population of patients who are doing well at moderate sublingual doses in opioid treatment programs that might transition to office-based care."
Novel Implant
"This novel implant system may help buttress patients' decision-making deficits that are a core component of the addiction by making these lifesaving medication adherence decisions far more infrequent," write Wilson M. Compton, MD, and Nora D. Volkow, MD, director of the National Institute on Drug Abuse, Bethesda, Maryland, in an accompanying editorial.
They note, however, that buprenorphine implants are currently approved in the United States for only up to 1 year for a subgroup of patients who have achieved and sustained prolonged clinical stability while receiving low to moderate doses of oral sublingual buprenorphine.
"Even so, this novel approach to delivering care may open up treatment for new, previously difficult-to-reach populations or for those in the criminal justice system," Dr Compton and Dr Volkow note. "Although further research is needed to determine which populations would benefit the most from these new formulations, the potential of these agents to have a positive role in the current opioid crisis is undeniable," they conclude.
The study was funded by Braeburn Pharmaceuticals. Dr Compton owns stock in Pfizer, General Electric, and 3M. The other authors and editorialists have disclosed no relevant financial relationships.
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Cite this: Buprenorphine Implant May Boost Opioid Abstinence - Medscape - Jul 19, 2016.
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