At a glance
ClinicalIndex Comparison Record- ✓Age ≥18 years
- ✓Smoke ≥10 non-menthol cigarettes per day
- ✓Of European ancestry
- ✓Willing and able to provide informed consent
- ✕Kidney disease or history of renal impairment without recent testing and physician approval
- ✕Alcohol use >25 standard drinks/week
- ✕Active hepatitis (LFTs ≥3× ULN)
- ✕History of opiate dependence
Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.
Pharmacogenetic Investigation of Naltrexone
In Brief
A Phase 2 clinical trial evaluating Naltrexone and Placebo for Tobacco Dependence. Completed, enrolled 64 participants across 1 site.
Detailed Summary
Despite preclinical evidence supporting the role of the endogenous opioid system in the reinforcing effects of nicotine, the efficacy of the opioid antagonist naltrexone (NTX) as a tobacco dependence treatment remains unresolved. Research is needed to identify those smokers for whom NTX will have the strongest beneficial effects on smoking behavior. The research bridges existing knowledge of genetic, pharmacologic, and behavioral responses to nicotine, and translates this knowledge to treatment for tobacco dependence. The immediate goal was to test whether genetic variation in the mu-opioid receptor gene predicts the effects of naltrexone (NTX) on nicotine reinforcement.
Study Details
Timeline
Interventions
All participants took naltrexone during one of the two 4-day study medication periods. Both 4-day study medication periods were randomized and counterbalanced between naltrexone and placebo; all study medication periods were separated by a 5-7 day washout period. Dosing of the naltrexone was the same for all participants: Day 1: 12.5mg, Day 2: 25mg, Days 3 and 4: 50mg.
All participants took a placebo (sugar pill) during one of the two 4-day study medication periods. Both 4-day study medication periods were randomized and counterbalanced between naltrexone and placebo. Placebo capsules matched the naltrexone in color, weight and inactive ingredients. The only difference the lack of active naltrexone in each capsule.