Longer duration of buprenorphine tapering regime is significantly associated with superior outcomes in treatment for prescription opioid addiction, a double-blind randomized trial has found. The study was published online Oct. 23 in JAMA Psychiatry.
"Our results suggest that a subset of [prescription opioid] abusers may respond favorably to a brief but carefully crafted outpatient treatment involving buprenorphine detoxification, naltrexone maintenance, and behavioral therapy," wrote Stacey C. Sigmon, Ph.D., of the University of Vermont, Burlington, and her colleagues.
In the trial, 70 prescription opioid–dependent adults aged 18 and older were randomized to 1-, 2-, or 4-week buprenorphine tapering regimes after initial stabilization with buprenorphine and naloxone hydrochloride dihydrate, the investigators reported.
All of the adults met the DSM-IV criteria for opioid dependence. The mean age was 27 years; 35 of the patients (49%) were aged 25 or younger. Patients requiring opioids for pain, pregnant or nursing women, and individuals with significant or unstable psychiatric or medical illnesses were excluded (JAMA Psychiatry 2013 Oct 23 [doi:10.1001/jamapsychiatry.2013.2216]).
Half of patients randomized to the 4-week regime were retained, abstinent, and receiving naltrexone at the end of the study (6-12 weeks after randomization), compared with 17% of patients on the 2-week regime and 21% of patients on the 1-week regime (P = 0.03).
The 4-week taper was associated with fourfold greater odds of favorable treatment response, compared with the 1-week taper (odds ratio 4.1; 95%CI, 1.1-16.0, P = .04) and nearly sixfold greater odds than the 2-week taper (OR 5.9; 95% CI, 1.4-24.7; P = .01), according to the study.
"When percentage of opioid-negative specimens was collapsed across all study visits, the percentage of negative specimens observed in the 4-, 2-, and 1-week conditions was 58% (n = 13), 35% (n = 8), and 38% (n = 9), respectively (P = .07)," Dr. Sigmon reported.
A recent review had suggested a positive association between buprenorphine taper duration and treatment outcomes, but the researchers said there was generally a dearth of empirical data on treatments for prescription opioid dependence.
The medications were administered in a double-blind, double-dummy manner, and participants received naltrexone maintenance therapy after the tapering period to reduce the likelihood of relapse. All participants were given individual behavioral therapy based on the Community Reinforcement Approach, which the investigators said has been shown to be efficacious with alcohol, cocaine, and opioid-dependent outpatients.
Patients visited the clinical daily during phase 1 of the trial (weeks 1-5 after randomization), then three times weekly in phase 2 (6-12 weeks after randomization).
One study limitation cited by the authors was the absence of a comparison group receiving buprenorphine maintenance therapy, which would have enabled a comparison between taper and continued administration.
"Although this study offers a rigorous evaluation of buprenorphine taper duration and naltrexone maintenance in [prescription opioid–dependent patients], there was no effort to isolate the effects of the behavioral therapy," the researchers wrote. "Thus, the contribution of the Community Reinforcement Approach to outcomes is unknown."
They also said the results might not be generalizable to the larger population, because adults in their study were mainly white and reported oxycodone as the main drug of abuse. "However, most [prescription opioid] users are white, and oxycodone is one of the most commonly used [prescription opioids]," Dr. Sigmon and colleagues said.
Future studies might seek to "disentangle abstinence and retention, perhaps by offering financial incentives contingent on study completion," they wrote.
Dr. Sigmon disclosed ties with Alkermes and Titan Pharmaceuticals. The study was funded by the National Institute on Drug Abuse (NIDA), and medications and placebo tablets were provided by Reckitt Benckiser Pharmaceuticals through NIDA.