Phenobarbital and/or benzodiazepines for recurrent alcohol withdrawal: A self-controlled, retrospective cohort study

Is Phenobarbital an Effective Treatment for Alcohol Withdrawal Syndrome?

BACKGROUND

Alcohol use disorder is associated with a variety of complications, including alcohol withdrawal syndrome (AWS), which may occur in those who decrease or stop alcohol consumption suddenly. AWS is associated with a range of signs and symptoms, which are most commonly treated with GABAergic medications.

CLINICAL QUESTION

Is phenobarbital an effective treatment for AWS?

EVIDENCE REVIEW

Studies retrieved included two prospective, randomized, double-blind studies and three systematic reviews. These studies provided estimates of the effectiveness and safety of phenobarbital for treatment of AWS.

CONCLUSIONS

Based on the available literature, phenobarbital is reasonable to consider for treatment of AWS. Clinicians must consider the individual patient, clinical situation, and comorbidities when selecting a medication for treatment of AWS.

Phenobarbital Versus Benzodiazepines for the Treatment of Severe Alcohol Withdrawal

BACKGROUND

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

OBJECTIVE

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

METHODS

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.

RESULTS

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).

CONCLUSION AND RELEVANCE

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.

Phenobarbital treatment of alcohol withdrawal in the emergency department: A systematic review and meta-analysis

OBJECTIVE

Despite frequent treatment of alcohol withdrawal syndrome (AWS) in the emergency department (ED), evidence for phenobarbital (PB) as an ED alternative therapy is mixed. We conducted a systematic review and meta-analysis comparing safety and efficacy of PB to benzodiazepines (BZDs) for treatment of AWS in the ED.

METHODS

We searched articles and references published in English in PubMed, Web of Science, and Embase from inception through May 2022. We included randomized trials and cohort studies comparing treatment with PB to BZD controls and excluded studies focused on non-AWS conditions. Review was conducted by two blinded investigators and a third author; eight of 59 (13.6%) abstracts met inclusion criteria for review and meta-analysis using a random-effects model. Treatment superiority was evaluated through utilization, pharmacologic, and clinical outcomes. Primary outcomes for meta-analysis were the proportion of patients (1) admitted to the intensive care unit (ICU), (2) admitted to the hospital, (3) readmitted to the ED after discharge, and (4) who experienced adverse events.

RESULTS

Eight studies (two randomized controlled trials, six retrospective cohorts) comprised data from 1507 patients in 2012 treatment encounters for AWS. All studies were included in meta-analysis for adverse events, seven for hospital admission, five for ICU admission, and three for readmission to the ED after discharge. Overall methodological quality was low-moderate, risk of bias moderate-high, and statistical heterogeneity moderate. Pooled relative risk of ICU admission for those treated with PB versus BZD was 0.92 (95% confidence interval [CI] 0.54-1.55). Risk for admission to the hospital was 0.98 (95% CI 0.89-1.07) and for any adverse event was 1.1 (95% CI 0.78-1.57); heterogeneity prevented meta-analysis for ED readmission.

CONCLUSIONS

The current literature base does not show that treatment with PB significantly reduces ICU admissions, hospital admissions, ED readmissions, or adverse events in ED patients with AWS compared with BZDs alone.

Phenobarbital for alcohol withdrawal in the context of the opioid epidemic: a neglected caveat

Phenobarbital interacts with the mortality-reducing opioid agonist therapies buprenorphine and methadone, risking delayed opioid withdrawal and relapse when administered concurrently. With increased adoption of phenobarbital into alcohol withdrawal protocols there should be safeguards in place to—in most cases—avoid phenobarbital for patients with a concurrent opioid use disorder.

Current evidence and clinical utility of phenobarbital for alcohol withdrawal syndrome

BACKGROUND

Phenobarbital (PB) has been acknowledged among clinicians as a potential alternative to benzodiazepines (BZD) to decrease the need for hospital length of stay and complications associated with alcohol withdrawal syndrome (AWS). However, the level of evidence, including appropriate dosing, is unclear. We aim to summarize the evidence regarding PB used in AWS and provide future agendas for research.

METHODS

Following the PRISMA guidelines, we searched MEDLINE, EMBASE, ClinicalTrials.gov, and WHO ICTRP for all peer-reviewed articles and clinical trials using keywords including"alcohol withdrawal", "delirium tremens", "phenobarbital," and "barbiturate" from their inception to September 18, 2022.

RESULTS

We included 20 articles, nine in the emergency department (ED) and 11 in the general floors or intensive care units (ICUs). Studies performed in the ED included two RCTs, although both suffered from a considerably small sample size. Six studies done in the general floors or ICUs compared PB and BZD monotherapy, while four compared the utility of adjunct PB in addition to BZD compared with BZD monotherapy and one was a database study without specific dosing information. Overall, there was considerable heterogeneity in PB dosing, measured outcomes, and AWS severity measurement scales.

CONCLUSION

This systematic review summarizes the current evidence related to PB use in AWS. While considerable heterogeneity exists among studies available, PB as monotherapy without BZD may be a safe and effective alternative in AWS treatment. Future prospective studies or trials should focus on the standardization of PB dosing and outcomes.

A retrospective evaluation of phenobarbital versus benzodiazepines for treatment of alcohol withdrawal in a regional Canadian emergency department

Evidence suggests that phenobarbital can be used to treat alcohol withdrawal syndrome as monotherapy; however, the therapeutic cornerstone remains benzodiazepines. To date, studies comparing the two treatment modalities in the emergency department (ED) are few. We sought to determine whether phenobarbital versus benzodiazepine monotherapy impacts ED length of stay and need for admission among adult presentations at a single regional hospital. In June 2019, a treatment algorithm offering both phenobarbital and diazepam pathways was introduced at the Battlefords Union Hospital ED, an 11-bed unit treating 27 000 patients annually in North Battleford, Saskatchewan, Canada. A subsequent retrospective observational study evaluated all adult alcohol withdrawal syndrome presentations between June 2019 and January 2021. Medical records were reviewed for visit date, age, sex, comorbidities, psychosocial factors, Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) scores, secondary diagnoses, time of day, protocol adherence, attending physician, length of stay, disposition, and ED return. Descriptive statistics, log-rank testing, simple regression, and multiple regression were used in analysis. Of the 184 presentations, 30.4% were treated with phenobarbital. Median length of stay for phenobarbital versus benzodiazepine therapy was 4.4 h and 4.4 h, respectively (p = 0.21). Of the phenobarbital presentations, 9.4% were hospitalized versus 17.1% of the benzodiazepine presentations (p = 0.20). When adjusted for confounders, phenobarbital-treated presentations were 71.3% less likely to be admitted (p = 0.03). This research suggests that phenobarbital performs similarly to benzodiazepines regarding alcohol withdrawal ED length of stay and may result in reduced hospitalizations.