Evaluation of Clinical Outcomes Associated With Phenobarbital With Taper Compared to No Taper for the Management of Alcohol Withdrawal Syndrome

Background: Phenobarbital (PHB) has been shown to be an effective treatment of alcohol withdrawal syndrome (AWS), with multiple dosing strategies used (e.g., single-dose and symptom-triggered). Studies have often used tapered doses, typically following a front-loaded dose, despite PHB's long half-life which should lead to an ability to auto-taper.Objective: The purpose of this study was to compare clinical outcomes associated with two PHB dosing strategies (taper [T], no taper [NT]) for AWS.Methods: This retrospective cohort study compared adult patients admitted to the ICU from October 2017 to May 2019 who received an initial loading dose of PHB for AWS. The use of PHB was at the discretion of the clinician per our institutional guidelines. Prior to November 2018, patients were prescribed a PHB taper, while after this period, the taper was no longer recommended. The primary outcome was the proportion of patients requiring rescue PHB or adjunctive medications for AWS. Secondary outcomes included number of adjunctive agents used, prevalence of severe manifestations of AWS, ICU and hospital lengths of stay, and incidence of potentially significant drug interactions.Results: A total of 172 patients were included (T: n = 81, NT: n = 91). Baseline characteristics were similar between groups, including history of severe AWS and cumulative benzodiazepine dose pre-PHB. There was no difference in the primary outcome between groups (T: 70.4% vs NT: 59.3%, P = 0.152). The median number of adjunctive agents per patient, severe manifestations, and ICU and hospital length of stay did not differ between groups. Twenty-five patients (14.5%) had potentially significant drug interactions.Conclusion and Relevance: The use of a PHB loading dose without a taper may be comparable to a taper strategy on clinical outcomes. Prospective studies are needed to further delineate the optimal dose of PHB for AWS.