Naltrexone treatment is more effective for heavy drinkers who use nicotine/cigarettes

Study participants (n=146; 101 males, 45 females) were enrolled in a 16-week randomized clinical trial comparing naltrexone with placebo treatment. All participants met Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria for alcohol dependence. After initial assessment, they were genotyped for the OPRM1 A118G SNP and balancing on whether they used nicotine/cigarettes were randomly assigned to be treated with either naltrexone (50 mg/day) or placebo. The researchers assessed and analyzed alcohol use and smoking during the trial.

Results confirmed previous findings that naltrexone is more effective for alcohol dependent individuals who also use nicotine/cigarettes. Nicotine users/smokers showed a significantly lower percentage of heavy-drinking days (confirmed by a blood test for heavy drinking) while receiving naltrexone versus placebo. The effect was not seen in non-nicotine users (non-smokers). Naltrexone did not change cigarette use by smokers during the study, and the change in smoking did not influence whether naltrexone reduced alcohol consumption. However, the authors noted that participants were not seeking smoking cessation, and medical management did not address this issue. They hypothesized that excess brain dopamine release in heavy alcohol users who also use nicotine/smoke could make them more treatment-resistant in general, but more sensitized to naltrexone's dopamine lowering effects -- leading to their greater response to treatment with the medication than non-smokers.