Effects of Prazosin Treatment on Liver Enzymes Are Moderated by Alcohol Withdrawal Symptoms in Individuals with Alcohol Use Disorder

Background: Alcohol use disorder (AUD) is associated with significant liver pathology marked by elevated liver enzymes. Prazosin, an alpha1-noradrenergic antagonist significantly improves alcohol drinking outcomes in individuals with alcohol withdrawal symptoms (AW), but effects on liver enzymes are unknown. We assessed the effects of prazosin treatment on the liver enzymes alanine transaminase (ALT), aspartate transaminase (AST), and gamma-glutamyltransferase (GGT) in individuals with AUD.

Methods: Participants (N=100) with AUD were enrolled in a 12-week randomized controlled trial and received either placebo or 16 mg/day of prazosin. Whole blood was drawn from 92 participants to measure liver enzyme levels every 4 weeks, and severity of AW was assessed weekly. Analysis predicting liver function outcomes used linear mixed effects models.

Results: Controlling for alcohol consumption, a significant AW × treatment effect was seen for ALT (p < 0.05), AST (p < 0.05) and GGT (p < 0.01). Additionally, AST (b = 0.2, p < 0.01), ALT (b = 0.2, p < 0.05), and GGT (b = 0.3, p < 0.01) were elevated in individuals with higher AW in the placebo but not in the prazosin group (AST: p > 0.66; ALT: p > 0.65). Only in the prazosin group were lower GGT levels associated with higher withdrawal severity (b = -0.16, p < 0.05).

Conclusions: We found an interaction of alcohol withdrawal symptoms and prazosin treatment on liver enzyme levels, which were not influenced by week in the trial or the amount of alcohol consumed. Together, these findings suggest that prazosin treatment reduces liver enzymes over the course of AUD treatment among individuals with significant AW, though replication to establish clinical utility is needed.