“This study supports the growing body of work suggesting that α-1 noradrenergic antagonists that cross the blood-brain barrier may help people limit unsafe heavy drinking,” wrote Tracy L. Simpson, Ph.D., of the VA Puget Sound Health Care System and colleagues.
Simpson and colleagues previously conducted a pilot study of 24 adults with alcohol dependence treated with prazosin for six weeks; the study found that those treated with prazosin reported fewer drinking days toward the end of the six-week trial than those treated with placebo. For the current study, the researchers assigned 92 participants with alcohol use disorder to receive prazosin or placebo in a 12-week double-blind study.
The study participants attended twice-weekly study visits during weeks 1 and 2—as prazosin was titrated (target dosing of 4 mg in the morning, 4 mg in the afternoon, and 8 mg at bedtime)—and then weekly study visits weeks 3 through 12. During the study visits, the researchers collected urine (to measure medication adherence), checked patient vitals such as blood pressure, and assessed the medication’s effects. Additionally, participants were asked to complete 4- to 5-minute interactive voice response calls daily to report the previous day’s drinking, cravings, and study medication doses consumed.
Analysis of data from the 80 participants who completed the two-week titration phase revealed that days of heavy drinking (≥4 drinks for women, ≥5 drinks for men) decreased more rapidly from week 3 to week 12 in the prazosin group than in the placebo group. Similarly, from week 3 to week 12, the prazosin group reduced the number of drinks per week by 8.0, compared with 1.5 for the placebo group. In contrast, at week 12 there was no difference between the two groups in the total number of drinking days or in craving changes over time, the authors noted. Participants in the prazosin condition were more likely to report drowsiness and edema than participants in the placebo condition.
“These results indicate that prazosin has the potential to reduce the likelihood of heavy drinking and number of drinks per week over time but not the number of drinking days per week,” Simpson and colleagues wrote. “[P]razosin may be most useful in reducing heavy drinking associated with negative consequences, which is consistent with a harm reduction approach characterized by safer consumption rather than full abstinence.”
For related information, see the Psychiatric News article “Varenicline May Lower Heavy Drinking, Smoking In Men With AUD.”
(Image: iStock/Savushkin)