Efficacy of Varenicline in Methadone-Stabilized Cocaine Users
Cocaine addiction continues to be an important public health problem in the US with a significant cost to the individual and society. Among substance abusers, cocaine use has been recognized as a significant problem especially in methadone-maintenance patients. In several studies, rates of cocaine use have been reported to range from 30 to over 60 percent of those in methadone maintenance programs (Condelli et al. 1991; Hunt et al. 1984; Kidorf and Stitzer 1993; Kosten et al. 1988). In these patients, cocaine use seems to be a predictor of poor clinical outcome (Hartel et al. 1995; Kosten et al. 1987a). The development of effective pharmacotherapies for cocaine use disorders, especially in the opioid-dependent population is of great importance. Unfortunately, such effective pharmacotherapies do not exist.
- To determine the safety and tolerability of varenicline in cocaine-using methadone-stabilized subjects.
- To determine if varenicline is efficacious in reducing cocaine-use in methadone-stabilized subjects.
Drug: Sugar pill or Placebo
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Health Services Research
|Official Title:||Efficacy of Varenicline in Methadone-Stabilized Cocaine Users|
- Proportion of Cocaine Positive Urine Tests Per Week [ Time Frame: Weekly Measures over 12 weeks ] [ Designated as safety issue: No ]Urine samples were obtained thrice-weekly and analyzed for the presence of cocaine metabolites. Levels that exceeded 300 ng / ml on each individual urine test were considered positive. The primary outcome measure was the proportions of positive cocaine urine results per week that was calculated by using the total number of completed tests as the denominator and the total number of positive tests for that week as the numerator. This data was subjected to Hierarchical Linear Modeling (HLM) analysis using a total of 13 longitudinal results that included a baseline result (Week 0).
|Study Start Date:||March 2007|
|Study Completion Date:||August 2009|
|Primary Completion Date:||June 2009 (Final data collection date for primary outcome measure)|
|Active Comparator: Varenicline||
Varenicline up to 2 mg a day
Active Comparator: Sugar Pill or Placebo
Placebo is compared to active drug varenicline
Drug: Sugar pill or Placebo
Other Name: Sugar pill
For this pilot study, we hope to recruit a total of 40 subjects, with 20 subjects in the varenicline group, and 20 into the placebo-control group. Assuming significant findings, these data will enable us to estimate a possible effect size for carrying-out a larger study. For preliminary analysis as a prelude to planning larger controlled studies, we will clinically require an effect size of 20% differences in the rates of cocaine positive urines or of self-reported cocaine use between the active medication and placebo groups. We will not adjust for these multiple comparisons to the placebo group since this is a pilot study, and use two-tailed significance level of 0.05 when we employ repeated measures analysis of variance (ANOVA) or Hierarchical Linear Modeling (HLM,see below) for statistical analysis over the 16-week study period.
An Amendment was made and a new Updated consent form to include new FDA findings for study medication Varenicline." Varenicline may also cause changes in behavior, agitation, depressed mood, suicidal ideation and suicidal behavior." Currently we have 30 subjects who have completed this study. This study is suspended due to these new concerns, Department of Veterans Affairs and the P.I. James Poling agreed.
Study has been published. (April 2011)
|United States, Connecticut|
|West Haven, Connecticut, United States, 06516|
|Principal Investigator:||James Poling, Ph.D.||Yale University|