(955) Phenobarbital Versus Benzodiazepines for Alcohol Withdrawal Syndrome in the Intensive Care Unit

Introduction: Benzodiazepines (BZD) have historically been the preferred treatment for alcohol withdrawal syndrome (AWS), as supported by the 2020 American Society of Addiction Medicine (ASAM) guidelines. Since alcohol modulates the same gamma-amino-butyric acid (GABA) receptor as BZDs, chronic alcohol users may not adequately respond to therapy. Phenobarbital (PB) is considered a reasonable alternative in the ASAM guidelines, by presenting a dual mechanism with GABA activation and glutamate antagonism. The purpose of this study is to evaluate ICU length of stay differences with IV PB versus an IV BZD for AWS.

Methods: This was a multi-center, institutional review board approved, retrospective cohort study. Adult patients were included if they were admitted to the ICU for AWS between January 2020 and March 2024, and were treated with either IV PB or an IV BZD for at least 24 hours. The primary outcome was ICU length of stay. Secondary outcomes included hospital length of stay, mortality, 30-day ICU and emergency department readmissions, maximum Clinical Institute Withdrawal Assessment (CIWA) score during treatment, alcohol-related seizure, alcohol hallucinosis and/or withdrawal delirium, and requirement of adjunct AWS treatment. Safety outcomes included need for mechanical ventilation, excessive sedation hypotension within 60 minutes of administration.

Results: A total of 38 patients were included in the study with 19 in each group. Baseline characteristics were well balanced, with the exception that more patients in the PB group received concomitant treatment with BZDs. The primary outcome of ICU length of stay showed no significant difference, with a median of 4.0 days [IQR, 3.0-8.0] in the PB group and 6.0 [IQR, 2.8-12.5] in the BZD group (p=0.23). For secondary outcomes, the PB group observed a numeric reduction in hospital length of stay, although not statistically significant (7.0 [IQR, 6.0-17.0] vs 14.0 [IQR, 7.0-21.0], p=0.13). There were additionally no significant differences in all secondary outcomes.

Conclusions: In patients treated in the ICU for AWS, there was no statistical difference in ICU length of stay between PB and BZDs, although the two-day numeric reduction may be clinically significant. Additional studies are necessary to determine PB’s role in the critical care setting for AWS.