Phenobarbital compared to benzodiazepines in alcohol withdrawal treatment: A register-based cohort study of subsequent benzodiazepine use, alcohol recidivism and mortality

SAEM GRACE: Phenobarbital for alcohol withdrawal management in the emergency department: A systematic review of direct evidence

OBJECTIVES

Alcohol withdrawal syndrome (AWS) is a commonly presenting condition in the emergency department (ED) and can have severe complications, including mortality. Benzodiazepines are first-line medications for treating AWS but may be unavailable or insufficient. This systematic review evaluates the direct evidence assessing the utility of phenobarbital for treating AWS in the ED.

METHODS

A systematic search was conducted and designed according to the patient-intervention-comparator-outcome (PICO) question: (P) adults (≥18 years old) presenting to the ED with alcohol withdrawal; (I) phenobarbital (including adjunctive); (C) benzodiazepines or no intervention; and (O) AWS complications, admission to a monitored setting, control of symptoms, adverse effects, and adjunctive medications. Two reviewers independently assessed articles for inclusion and conducted risk of bias assessments for included studies.

RESULTS

From 70 potentially relevant articles, seven studies met inclusion criteria: three retrospective cohort studies, two retrospective chart reviews, and two randomized controlled trials (RCTs), one examining phenobarbital monotherapy and one examining adjunctive phenobarbital. Across the retrospective cohort studies, treatment of AWS with phenobarbital resulted in lower odds of a subsequent ED visit. The retrospective chart reviews indicated that phenobarbital was associated with higher discharge rate compared to benzodiazepine-only treatments. For the two RCTs, phenobarbital did not differ significantly from benzodiazepine for most outcomes, although concomitant treatment with phenobarbital was associated with lower benzodiazepine use and intensive care unit admission. The heterogeneous designs and small number of studies prevented quantitative synthesis.

CONCLUSIONS

Relatively few studies provide direct evidence on the utility of phenobarbital for AWS in the ED, but the evidence that exists generally suggests that it is a reasonable and appropriate approach. Additional RCTs and other methodologically rigorous investigations are needed for more definitive direct evidence.

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.

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.

The Spectrum of Alcohol Use: Epidemiology, Diagnosis, and Treatment

In the United States, alcohol is the most common substance used and the spectrum of unhealthy alcohol use is highly prevalent. Complications of unhealthy alcohol use affect nearly every organ system. One of the most frequent and potentially life-threatening of these complications is alcohol withdrawal syndrome for which benzodiazepines remain first-line therapy. Pharmacologic treatment of alcohol use disorder, the most severe form of unhealthy alcohol use, is underutilized despite the availability of multiple effective medications. Although behavioral therapies are an important component of treatment, they are overemphasized at the expense of pharmacotherapy.

Affective Disruption During Forced Ethanol Abstinence in C57BL/6J and C57BL/6NJ Mice

BACKGROUND

In alcohol-dependent individuals, acute alcohol withdrawal results in severe physiological disruption, including potentially lethal central nervous system hyperexcitability. Although benzodiazepines successfully mitigate such symptoms, this treatment does not significantly reduce recidivism rates in postdependent individuals. Instead, persistent affective disturbances that often emerge weeks to months after initial detoxification appear to play a significant role in relapse risk; however, it remains unclear whether genetic predispositions contribute to their emergence, severity, and/or duration. Interestingly, significant genotypic and phenotypic differences have been observed among distinct C57BL/6 (B6) substrains, and, in particular, C57BL/6J (B6J) mice have been found to reliably exhibit higher voluntary ethanol (EtOH) intake and EtOH preference compared to several C57BL/6N (B6N)-derived substrains. To date, however, B6 substrains have not been directly compared on measures of acute withdrawal severity or affective-behavioral disruption during extended abstinence.

METHODS

Male and female B6J and B6NJ mice were exposed to either a 7-day chronic intermittent EtOH vapor (CIE) protocol or to ordinary room air in inhalation chambers. Subsequently, blood EtOH concentrations and handling-induced convulsions were evaluated during acute withdrawal, and mice were then tested weekly for affective behavior on the sucrose preference test, light-dark box test, and forced swim test throughout 4 weeks of (forced) abstinence.

RESULTS

Despite documented differences in voluntary EtOH intake between these substrains, we found little evidence for substrain differences in either acute withdrawal or long-term abstinence between B6J and B6NJ mice.

CONCLUSIONS

In B6J and B6NJ mice, both the acute and long-term sequelae of EtOH withdrawal are dependent on largely nonoverlapping gene networks relative to those underlying voluntary EtOH drinking.

Affective Behavior in Withdrawal Seizure-Prone and Withdrawal Seizure-Resistant Mice during Long-Term Alcohol Abstinence

BACKGROUND

While the acute alcohol withdrawal syndrome has been well characterized both in human clinical studies and in experimental animals, much less is known regarding long-term affective disturbances that can sometimes persist during protracted abstinence. Nevertheless, since relapse often occurs long after acute detoxification and may be predicted by persistent affective disruption, a better understanding of the long-term behavioral consequences of prior alcohol dependence may lead to improved strategies for relapse prevention.

METHODS

Male and female Withdrawal Seizure-Prone and Withdrawal Seizure-Resistant mice from the second selection replicate (WSP-2, WSR-2) were exposed to a 10-day chronic-intermittent ethanol vapor protocol (CIE) or plain air and then tested repeatedly on the sucrose preference test (SPT), marble burying test (MBT), and the light-dark box test (LDT) over 7 weeks of (forced) abstinence.

RESULTS

While WSP and WSR mice differed significantly on tests of anxiety-like behavior (LDT, MBT), we found little evidence for long-term affective disruption following CIE in either line. The major exception was in the LDT, in that WSP but not WSR mice displayed longer latencies to enter the light compartment following CIE relative to air-controls.

CONCLUSIONS

Selective breeding for acute withdrawal severity has resulted in differences in anxiety-like behavior between WSP and WSR mice. In contrast, however, genes contributing to the severity of acute withdrawal convulsions appear to have little overlap with those predisposing to affective disruption during long-term abstinence.

Emergency Medicine Research Priorities for Early Intervention for Substance Use Disorders

Introduction

Patients with substance use disorders (SUDs) frequently seek emergency care, and the emergency department (ED) may be their only point of contact with the healthcare system. While the ED visit has been increasingly recognized as providing opportunity for interventions around substance use, many questions remain.

Methods

In December 2016 the Coalition on Psychiatric Emergencies (CPE) convened the first Research Consensus Conference on Acute Mental Illness, which consisted of clinical researchers, clinicians from emergency medicine, emergency psychiatry, emergency psychology, representatives from governmental agencies and patient advocacy groups. Background literature review was conducted prior to the meeting, and questions were iteratively focused, revised, voted on and ranked by perceived importance using nominal group method.

Results

The main goal of the SUD workgroup was to identify research priorities and develop a research agenda to improve the early identification of and management of emergency department (ED) patients with SUDs with the goal of improving outcomes. This article is the product of a breakout session on “Special Populations: Substance Use Disorder.” The workgroup identified with high consensus six research priorities for their importance related to the care of ED patients with SUDs in these overall domains: screening; ED interventions; the role of peer navigators; initiation of SUD management in the ED; specific patient populations that may impact the effectiveness of interventions including sociogenerational and cultural factors; and the management of the acutely intoxicated patient.

Conclusion

Emergency providers are increasingly recognizing the important role of the ED in reducing adverse outcomes associated with untreated SUDs. Additional research is required to close identified knowledge gaps and improve care of ED patients with SUD.

Evaluating the Use of Phenobarbital for the Management of Alcohol Withdrawal Syndrome in Psychiatric Inpatients

OBJECTIVES

To describe the potential role of phenobarbital as appropriate therapy in the treatment and prevention of alcohol withdrawal syndrome (AWS) among medically cleared psychiatric inpatients.

METHODS

This was a single-center, retrospective, observational study of adult patients admitted to the psychiatric unit and administered phenobarbital for the treatment or prevention of AWS. Changes in vital signs and signs and symptoms of AWS were observed to assess the safety and efficacy of phenobarbital. The primary outcome was safety of phenobarbital for AWS as measured by change in the respiratory rate (RR).

RESULTS

A total of 122 patients were included in the study. There were no significant changes in RR among patients who received phenobarbital for AWS. Significant reductions in blood pressure and heart rate were observed. Of patients with documented signs and symptoms of AWS upon admission, 94% had improvement in the signs and symptoms during phenobarbital therapy. Approximately 12% of patients had documented sedation or altered mental status during phenobarbital therapy. No patients required transfer to a medical or critical care unit.

CONCLUSIONS

Phenobarbital was safe, not leading to severe adverse effects or requiring a higher level of care, and efficacious for the prevention and treatment of AWS in this cohort of psychiatric inpatients.

Inpatient Addiction Consult Service: Expertise for Hospitalized Patients with Complex Addiction Problems

Substance use disorders are highly prevalent and are a large driver of costly inpatient medical care; however, historically the substance use disorder has gone unaddressed during an inpatient stay. Inpatient addiction consult services are an important intervention to use the reachable moment of hospitalization to engage patients and initiate addiction treatment. Addiction consultation involves taking an addiction-specific history, motivational interviewing, withdrawal symptom management, and initiation of long-term pharmacotherapy. Addiction consult services have the potential to decrease readmissions and utilization costs for medical systems and improve substance-related outcomes for patients.

Molecular spectroscopic studies examining the interactions between phenobarbital and human serum albumin in alcohol consumption

BACKGROUND

Alcohol dependence is associated with a wide range of serious mental, physical, and social consequences and is one of the most common chronic diseases worldwide. Barbiturates, which are a first-line treatment in the clinic for alcohol withdrawal, may result in combined barbiturate and alcohol use. Their co-use abuse may promote synergistic effects between barbiturates and alcohol in vivo.

OBJECTIVE

To investigate the effects of different alcohol concentrations on the synergistic effects of phenobarbital and alcohol.

METHODS

The interactions between phenobarbital and human serum albumin (HSA) and the effects of different alcohol concentrations on the binding behaviors of the phenobarbital-HSA system were investigated by molecular docking and spectroscopic methods, including fluorescence spectroscopy and UV-visible absorption spectroscopy.

RESULTS

Experimental results revealed that phenobarbital can be stored and carried by HSA. The presence of alcohol (≤1.96 × 10^-2 M) can increase the proportion of free phenobarbital and shorten the half-life and storage time of phenobarbital in the blood, thereby enhancing its bioactive efficacy. The binding constants (K_b) of the phenobarbital-HSA system decrease in the presence of alcohol (≥2.61 × 10^-2 M), which suggests that phenobarbital should be quickly cleared from blood, thereby decreasing the activity of phenobarbital.

CONCLUSIONS

The effects of alcohol on the transposition of phenobarbital by HSA at the beginning of the barbiturate metabolic process play an important role in the synergistic effects of phenobarbital and alcohol. This mechanism may be significant for the clinical dosage of patients with alcohol dependence.

Patient Outcomes Associated With Phenobarbital Use With or Without Benzodiazepines for Alcohol Withdrawal Syndrome: A Systematic Review

Purpose: Benzodiazepines are the drug of choice for alcohol withdrawal syndrome (AWS); however, phenobarbital is an alternative agent used with or without concomitant benzodiazepine therapy. In this systematic review, we evaluate patient outcomes with phenobarbital for AWS. Methods: Medline, Cochrane Library, and Scopus were searched from 1950 through February 2017 for controlled trials and observational studies using ["phenobarbital" or "barbiturate"] and ["alcohol withdrawal" or "delirium tremens."] Risk of bias was assessed using tools recommended by National Heart, Lung, and Blood Institute. Results: From 294 nonduplicative articles, 4 controlled trials and 5 observational studies (n = 720) for AWS of any severity were included. Studies were of good quality (n = 2), fair (n = 4), and poor (n = 3). In 6 studies describing phenobarbital without concomitant benzodiazepine therapy, phenobarbital decreased AWS symptoms (P < .00001) and displayed similar rates of treatment failure versus comparator therapies (38% vs 29%). A study with 2 cohorts showed similar rates of intensive care unit (ICU) admission (phenobarbital: 16% and 9% vs benzodiazepine: 14%) and hospital length of stay (phenobarbital: 5.85 and 5.30 days vs benzodiazepine: 6.64 days). In 4 studies describing phenobarbital with concomitant benzodiazepine therapy, phenobarbital groups had similar ICU admission rates (8% vs 25%), decreased mechanical ventilation (21.9% vs 47.3%), decreased benzodiazepine requirements by 50% to 90%, and similar ICU and hospital lengths of stay and AWS symptom resolution versus comparator groups. Adverse effects with phenobarbital, including dizziness and drowsiness, rarely occurred. Conclusion: Phenobarbital, with or without concomitant benzodiazepines, may provide similar or improved outcomes when compared with alternative therapies, including benzodiazepines alone.