While buprenorphine has long been used to treat adults with opioid dependence, its efficacy can be hindered by the lack of adherence to daily, sublingual doses of the medication. New research led by the Icahn School of Medicine at Mount Sinai and published online in the Journal of the American Medical Association has shown that a higher percentage of stable, opioid-dependent patients given six-month buprenorphine implants remained abstinent compared with patients given the medication sublingually.
The study is the first head-to-head safety and efficacy trial of buprenorphine implants and daily sublingual buprenorphine for the long-term remission of opioid use disorder in patients who were previously stabilized on 8 mg or less of sublingual buprenorphine. The findings indicated that the implants were noninferior to sublingual buprenorphine in maintaining abstinence from illicit opioids in at least four of the six study months (the trial’s primary outcome measure).
“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,” said Richard N. Rosenthal, MD, a professor of psychiatry at the Icahn School of Medicine at Mount Sinai. “Given that transitioning to implants did not lead to increased craving or withdrawal symptoms and that the implants remained in place over the active treatment period, buprenorphine implants are an opportunity to reduce adherence issues and may improve efficacy in stable patients with opioid dependence.”
Opioids include oxycodone, hydrocodone, codeine, morphine, and fentanyl. This drug class reduces the intensity of pain signals reaching the brain and affects the brain areas controlling emotion, which diminishes the effects of a painful stimulus. As people use opioids repeatedly, their tolerance increases and they may not be able to maintain the source for the drugs. This can cause them to turn to seeing multiple physicians for prescriptions or to the black market for these drugs, and even to switch from prescription drugs to cheaper and riskier substitutes, such as heroin. Opioid dependence is a growing public health problem in the United States and globally; is associated with the spread of viruses, such as human immunodeficiency virus (HIV) and hepatitis C; and may result in fatal overdose when left untreated.
In the new study, 177 opioid-dependent subjects with stable abstinence were randomly assigned to receive sublingual buprenorphine with placebo implants or buprenorphine implants with sublingual placebo. During the six-month study, 86% of participants receiving implants and 72% of those receiving sublingual buprenorphine maintained abstinence from opioids.
“What we would like to address in future studies is the rate and predictors of relapse after implant discontinuation,” Rosenthal said. “Our population in this trial also had a high response rate in the control group, so further studies are needed in broader populations to assess the efficacy of buprenorphine implants versus sublingual buprenorphine in other settings.”