Gender differences with high-dose naltrexone in patients with co-occurring cocaine and alcohol dependence

This is a randomized, double-blind, placebo-controlled clinical trial that evaluated the efficacy of a higher-than-typical daily dose of naltrexone (150 mg/day), taken for 12 weeks, in 164 patients (n = 116 men and n = 48 women) with co-occurring cocaine and alcohol dependence. Patients were stratified by gender and then randomly assigned to either naltrexone or placebo, and to either cognitive–behavioral therapy or a type of medical management. The two primary outcomes were cocaine use and alcohol use. Significant Gender × Medication interactions were found for cocaine use via urine drug screens (three way, with time) and self-reports (two way) for drug severity (two way) and alcohol use (two way). The type of psychosocial treatment did not affect outcomes. Thus, 150 mg/day naltrexone added to a psychosocial treatment resulted in reductions in cocaine and alcohol use and drug severity in men, compared to higher rates of cocaine and alcohol use and drug severity in women.