Prazosin for Alcohol Dependence and Posttraumatic Stress Disorder

Background: Alcohol dependence (AD) is a biologically, genetically based disease, yet the majority of clinically accepted treatments are behaviorally or psychosocially based. PTSD and alcohol use disorders (AUDs) commonly co-occur. This comorbidity is associated with more severe clinical impairment, shorter times to relapse, more treatment recidivism, overall greater use of treatment services, and greater treatment costs. Neuropharmacology of alcohol and prazosin: Emerging pre-clinical evidence shows that noradrenergic systems are involved in brain processes relevant to AD, such as arousal, reinforcement, and stress responsivity. However, virtually no work to date has attempted to translate this knowledge into clinically effective biological interventions. The investigators have adopted the novel, promising strategy of reducing adrenergic activity by blocking noradrenaline binding to post-synaptic alpha-1 receptors via the non-selective, alpha-1 antagonist, prazosin. Preclinical studies have demonstrated that prazosin decreases reinstatement of alcohol consumption, and preliminary clinical data suggest that prazosin reduces alcohol use in humans with AD and reduces PTSD-related nightmares and other symptoms, though it has not been tested in individuals with comorbid AD and PTSD. Prazosin, FDA approved to treat hypertension, typically has few side effects, and is inexpensive. Design: Randomized double-blind placebo-controlled clinical trial. Participants: 60 individuals with both AD and PTSD (25% women) with stated goal to abstain from alcohol use. Intervention: Either prazosin titrated per study protocol or matched placebo for 6 weeks with Medical Management (MM) based on the COMBINE Study procedures and a final study visit two weeks after medication discontinuation. Measures: The primary outcomes are alcohol use during the 12-week medication phase of the study and reports of craving during the same time period. Daily, prompted Interactive Voice Response (IVR) telephone monitoring will be done throughout the 8-week study to assess the primary outcomes and to provide information on affect and medication adherence. Such daily monitoring provides more accurate reports of alcohol use than standard retrospective outcome measures. Analyses: Hierarchical linear modeling to test for main effects of prazosin+MM versus placebo+MM on alcohol use and PTSD symptoms over time, and to evaluate whether reductions in PTSD mediate the effect of prazosin. Findings to date: Participants randomized to prazosin had a greater reduction in percent days drinking per week and percent days heavy drinking per week between baseline and week 6 than did placebo participants. No significant differences were detected within or between groups in change from weeks 1 to 6 in total PTSD symptoms. Participants in the prazosin condition reported drowsiness on significantly more days than those in the placebo condition. Public health implications: There is a paucity of safe, tolerable, inexpensive, and efficacious drugs currently available for the treatment of AD and PTSD. Consistent with the extant research evaluating medications for comorbid PTSD/AD, the current evaluation of prazosin also found decreased alcohol consumption but no medication effect on PTSD symptomatology.