A Randomized, Double-blind Evaluation of Buprenorphine Taper Duration in Primary Prescription Opioid Abusers

Abstract

Although abuse of prescription opioids (POs) is a significant public health problem, few experimental studies have investigated the treatment needs of this growing population. To evaluate, following brief stabilization with a combination of buprenorphine hydrochloride and naloxone hydrochloride dihydrate, the relative efficacy of 1-, 2-, and 4-week buprenorphine tapering regimens and subsequent naltrexone hydrochloride therapy in PO-dependent outpatients. A double-blind, 12-week randomized clinical trial was conducted in an outpatient research clinic. Following a brief period of buprenorphine stabilization, 70 PO-dependent adults were randomized to receive 1-, 2-, or 4-week tapers followed by naltrexone therapy. During phase 1 (weeks 1-5 after randomization), participants visited the clinic daily; during phase 2 (weeks 6-12), visits were reduced to thrice weekly. Participants received behavioral therapy and urine toxicology testing throughout the trial. The percentage of participants negative for illicit opioid use, retention, naltrexone ingestion, and favorable treatment response (ie, retained in treatment, opioid abstinent, and receiving naltrexone at the end of the study). Opioid abstinence at the end of phase 1 was greater in the 4-week compared with the 2- and 1-week taper conditions (P = .02), with 63% (n = 14), 29% (n = 7), and 29% (n = 7) of participants abstinent in the 4-, 2-, and 1-week conditions, respectively. Abstinence at the end of phase 2 was also greater in the 4-week compared with the 2- and 1-week conditions (P = .03), with 50% (n = 11), 16% (n = 4), and 20% (n = 5) of participants abstinent in the 4-, 2-, and 1-week conditions, respectively. There were more treatment responders in the 4-week condition (P = .03), with 50% (n = 11), 17% (n = 4), and 21% (n = 5) of participants in the 4-, 2-, and 1-week groups considered responders at the end of treatment, respectively. Retention and naltrexone ingestion also were superior in the 4-week vs briefer tapers (both P = .04). Experimental condition (ie, taper duration) was the strongest predictor of treatment response, followed by buprenorphine stabilization dose. This study represents a rigorous experimental evaluation of outpatient buprenorphine stabilization, brief taper, and naltrexone maintenance for treatment of PO dependence. Results suggest that a meaningful subset of PO-dependent outpatients may respond positively to a 4-week taper plus naltrexone maintenance intervention.