A Retrospective Evaluation of Phenobarbital and Benzodiazepine Monotherapy and Combined Therapy in the Treatment of Alcohol Withdrawal Syndrome in a Canadian Emergency Department

Purpose The first-line treatment for alcohol withdrawal syndrome (AWS) in the emergency department (ED) is benzodiazepines. Phenobarbital is used as an alternative first-line treatment for AWS in admitted patients. This retrospective cohort study assessed the safety and efficacy of phenobarbital and benzodiazepines as first-line treatments of AWS in a Canadian ED. Methods A retrospective chart review was performed of patients seen at a Canadian tertiary care ED from January 2022 until December 2023. Patients were included if they were treated in the ED for AWS with phenobarbital or benzodiazepines, either as monotherapy or as combined therapy. The primary outcome was the time from medication administration to disposition (discharge or admission). Secondary outcomes included ED length of stay, time to medication administration, admission rates, 48-hour ED return visits, and adverse events. Statistical comparisons were performed using ANOVA and chi-square testing with post hoc analyses. Results A total of 342 patient encounters were included. The majority of patients (n = 203) were treated with benzodiazepine monotherapy, and 97 patients were treated with phenobarbital monotherapy. There was no significant difference in the primary outcome between the phenobarbital and benzodiazepine monotherapy groups. Combined use of phenobarbital and benzodiazepines was associated with a longer time to disposition, potentially reflecting patients with more severe symptoms or treatment-resistant cases. Overall, adverse events occurred in 11% of patients, with no significant difference between phenobarbital and benzodiazepine monotherapy groups. Conclusion Patients treated with phenobarbital monotherapy for AWS in the ED had a similar time from medication administration to ED disposition when compared to patients treated with benzodiazepine monotherapy. Phenobarbital monotherapy may be an appropriate first-line therapy for AWS in the ED; however, prospective studies are required.