(924) Phenobarbital for Alcohol Withdrawal Syndrome in Medical Intensive Care Unit Patients With Cirrhosis

Introduction: Phenobarbital has been studied extensively for the treatment of alcohol withdrawal syndrome (AWS), however it undergoes significant hepatic metabolism. Due to this, most studies in AWS have excluded patients with a history of cirrhosis. Therefore, the potential benefits or harms of utilizing phenobarbital in this patient population are unknown. The goal of this study is to describe phenobarbital dosing regimens, safety, and efficacy in patients with cirrhosis for the management of AWS being treated in a medical intensive care unit (MICU).

Methods: This was a retrospective descriptive study of adult patients with cirrhosis admitted to the MICU who received phenobarbital for the prevention or treatment of AWS between July 2018 - July 2023. The primary objective was to describe the dose, frequency, and duration of phenobarbital therapy. Secondary objectives were to describe rates of respiratory depression and progression to complicated AWS, defined as the development of delirium tremens or seizures, following phenobarbital administration.

Results: The analysis included 24 patients. The median age was 44 (IQR 34-64), 15 (62.5%) were male, the median MELD-Na was 17 (IQR 15-24), and 15 (62.5%) had a history of complicated or uncomplicated AWS. A phenobarbital loading dose, defined as a dose ≥ 260 mg, was administered to 15 (62.5%) patients, with a median loading dose of 260 mg (IQR 260-260). The median total phenobarbital dose within the first 24 hours was 520 mg (IQR 260-535) and the total dose during the course of therapy was 715 mg (IQR 535-1088). The median duration of therapy was 2.5 days (IQR 1.5-5). New supplemental oxygen within 48 hours of phenobarbital administration was required in 2 (15.4%) patients and 0 required new intubation. Complicated AWS developed in 8 (33.3%) patients, of which 7 (29.2%) developed delirium tremens and 1 (4.2%) developed seizures. Ten (41.6%) patients required adjunctive agents to treat AWS.

Conclusions: This study suggests the safety of utilizing phenobarbital in cirrhosis as evidenced by low rates of new oxygen requirements and no need for intubation. The optimal dosing of phenobarbital is yet to be determined in this population as many patients required adjunctive agents and developed complicated AWS.