Background Stress, alcohol cues and dysregulated stress responses increase alcohol craving and relapse susceptibility, but few pharmacologic agents are known to decrease stress and cue-induced alcohol craving and associated stress dysregulation in humans. Here we report findings from a preliminary efficacy study of the alpha1 receptor antagonist, prazosin, in modulating these relapse-relevant factors in alcohol dependent (AD) individuals. Methods Seventeen early abstinent, treatment-seeking alcohol dependent individuals (12 Males /5 Females) were randomly assigned to receive either placebo or 16 mg daily prazosin in a double-blind, placebo controlled manner over four weeks. During week 4, all patients participated in a 3-day laboratory experiment involving 5-min guided imagery exposure to stress, alcohol cue and neutral-relaxing/control conditions, one exposure per day, on consecutive days in a random, counterbalanced order. Alcohol craving, anxiety and negative emotion, cardiovascular measures, plasma hypothalamic-pituitary-adrenal (HPA; cortisol, ACTH) were assessed repeatedly in each session. Results The prazosin group (n=9) versus the placebo group (n=8) showed significantly lower alcohol craving, anxiety and negative emotion following stress exposure. The placebo group also showed significantly increased stress and cue-induced alcohol craving, anxiety, negative emotion and blood pressure as well as a blunted HPA response relative to the neutral condition, while the prazosin group showed no such increases in craving, anxiety, negative emotion and blood pressure, and no blunted HPA response to stress and alcohol cue exposure. Conclusions Prazosin appears efficacious in decreasing stress- and cue-induced alcohol craving and may normalize the stress dysregulation associated with early recovery from alcoholism. Further research to assess the efficacy of prazosin in reducing alcohol craving and stress-related relapse risk is warranted.

Although preliminary, these findings are the first to document lofexidine's potential in addressing stress-related opioid craving and relapse outcomes in humans. The results also suggest that combination therapies that target both drug-related reinforcement (naltrexone) and stress- and cue-related aspects of drug seeking could be beneficial in addiction relapse prevention. Further development of lofexidine to address stress-related opioid craving and relapse is warranted.

Cocaine dependence is associated with increased stress and drug cue-induced craving and physiological arousal but decreased prefrontal activity to emotional and cognitive challenge. As these changes are associated with relapse risk, we investigated the effects of α2 receptor agonist guanfacine on these processes. Twenty-nine early abstinent treatment-seeking cocaine dependent individuals were randomly assigned to either daily placebo or guanfacine (up to 3 mg) for four weeks. In a laboratory experiment, all patients were exposed to three 10-min guided imagery conditions (stress/stress, drug cue/drug cue, stress/drug cue), one per day, consecutively in a random, counterbalanced order. Subjective craving, anxiety and arousal as well as cardiovascular output were assessed repeatedly. Brain response to stress, drug cue and relaxing imagery was also assessed during a functional magnetic resonance (fMRI) imaging session. In the current study, guanfacine was found to be safe and well-tolerated. Lower basal heart rate and blood pressure was observed in the guanfacine versus placebo group. Guanfacine lowered stress and cue-induced nicotine craving and cue-induced cocaine craving, anxiety and arousal. The guanfacine group also showed increased medial and lateral prefrontal activity following stress and drug cue exposure compared with placebo. Data suggest further exploration of guanfacine is warranted in terms of its potential for reducing stress-induced and cue-induced drug craving and arousal.