Phenobarbital Versus Benzodiazepines for the Treatment of Severe Alcohol Withdrawal

Phenobarbital may offer advantages over benzodiazepines for severe alcohol withdrawal syndrome (SAWS), but its impact on clinical outcomes has not been fully elucidated.

The purpose of this study was to determine the clinical impact of phenobarbital versus benzodiazepines for SAWS.

This retrospective cohort study compared phenobarbital to benzodiazepines for the management of SAWS for patients admitted to progressive or intensive care units (ICUs) between July 2018 and July 2022. Patients included had a history of delirium tremens (DT) or seizures, Clinical Institute Withdrawal Assessment of Alcohol-Revised (CIWA-Ar) >15, or Prediction of Alcohol Withdrawal Severity Scale (PAWSS) score ≥4. The primary outcome was hospital length of stay (LOS). Secondary outcomes included progressive or ICU LOS, incidence of adjunctive pharmacotherapy, and incidence/duration of mechanical ventilation.

The final analysis included 126 phenobarbital and 98 benzodiazepine encounters. Patients treated with phenobarbital had shorter median hospital LOS versus those treated with benzodiazepines (2.8 vs 4.7 days; P < 0.0001); a finding corroborated by multivariable analysis. The phenobarbital group also had shorter median progressive/ICU LOS (0.7 vs 1.3 days; P < 0.0001), and lower incidence of dexmedetomidine (P < 0.0001) and antipsychotic initiation (P < 0.0001). Fewer patients in the phenobarbital group compared to the benzodiazepine group received new mechanical ventilation (P = 0.045), but median duration was similar (1.2 vs 1.6 days; P = 1.00).

Scheduled phenobarbital was associated with decreased hospital LOS compared to benzodiazepines for SAWS. This was the first study to compare outcomes of fixed-dose, nonoverlapping phenobarbital to benzodiazepines in patients with clearly defined SAWS and details a readily implementable protocol.