Induction onto Extended-release Naltrexone in 302 Cocaine-dependent Opioid Users
Year of Publication
Lindblad, R; McCormack, J; Saxon, A; Hillhouse, M; Thomas, C; Hasson, A; Mooney, L; Van Veldhuisen, P; Ling, W
College on Problems of Drug Dependence Meeting
San Diego CA
Aims: The National Institute on Drug Abuse Clinical Trials Network launched the Cocaine Use Reduction with Buprenorphine study in cocaine-dependent opioid users. Subjects were inducted onto 380 mg extended-release injectable naltrexone (XR-NTX) and randomly assigned to buprenorphine/naloxone (BUP) or placebo to assess the effect of BUP on cocaine use. Our aim is to describe the XR-NTX induction process and associated complications. Methods: Eligibility criteria include being cocaine dependent (DSM-IV), having DSM-IV past-year opioid dependence or abuse or past-year use (self report) and a lifetime history of opioid dependence (DSM-IV), being opioid detoxified per study physician’s assessment, and having a pre-induction urine drug screen (UDS) negative for opioids. Subjects were given a Naloxone (NAL) challenge of > a 0.8mg injection. If no opioid withdrawal symptoms were noted, oral naltrexone (ONX) (total 50mg) was administered. Again, if no signs of withdrawal were seen, XRNTX was administered to provide one month of opioid blockade. Results: 712 subjects consented. 78 subjects did not have a valid UDS negative for opioids and were not eligible for NAL. 317 received NAL. 314 received ONX, and one adverse event of withdrawal symptoms was reported after ONX. 302/317 received XR-NTX, for a 95% completion rate. The median time from NAL to XRNTX was 2 hrs, with 75% receiving it within 24 hrs. Conclusions: Relying on both objective (UDS) and subjective (self report) measures was adequate to identify cases able to receive NAL. Utilizing the NAL challenge allowed testing the no-use self report with the objective UDS in a clinical setting where precipitated withdrawal would be short lasting and medically manageable on an outpatient basis. Induction time variation reflected differences in site procedures. A structured approach in a population of cocaine-dependent opioid users proved to be safe and efficient to induct subjects onto XR-NTX.