When is a oral Phenobarbital (Pheno Barb) order considered for a hospitalized patient on the Clinical Institute Withdrawal Assessment (CIWA) protocol?

From the Guidelines

Oral phenobarbital is considered for hospitalized patients on the CIWA protocol when they demonstrate severe alcohol withdrawal symptoms that are refractory to benzodiazepine treatment, or when they require escalating doses of benzodiazepines without adequate symptom control, typically with CIWA scores above 15. When managing alcohol withdrawal syndrome (AWS), the Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) score is useful in determining the severity of symptoms 1. A CIWA-Ar score >8 indicates a moderate AWS and a score ≥15 indicates severe AWS, at which point pharmacological treatment is recommended using a symptom-triggered regimen rather than fixed dose schedule in order to prevent the accumulation of the drug 1. Benzodiazepines are considered the ‘gold standard’ treatment for AWS, given their efficacy for reducing both withdrawal symptoms and the risk of seizures and/or delirium tremens 1. However, in cases where benzodiazepines are not effective, or when patients require escalating doses without adequate symptom control, oral phenobarbital may be considered as an adjunctive treatment. The standard approach involves administering phenobarbital 60-120 mg orally every 6 hours as scheduled or as-needed dosing, with close monitoring of sedation levels and vital signs. Phenobarbital is effective in this scenario because it works on GABA receptors through a different mechanism than benzodiazepines, providing additional inhibitory effects in the central nervous system. However, caution is necessary due to phenobarbital's potential for respiratory depression, especially when combined with benzodiazepines, and its narrow therapeutic window 1. Patients receiving phenobarbital require close monitoring of respiratory status, level of consciousness, and vital signs throughout treatment. Key considerations for the use of phenobarbital in this context include:

• Monitoring for signs of benzodiazepine tolerance or refractory symptoms
• Close observation of sedation levels and vital signs
• Adjusting dosing regimens as needed to balance efficacy and safety
• Being aware of the potential for respiratory depression and taking steps to mitigate this risk.

From the FDA Drug Label

Treatment of barbiturate dependence consists of cautious and gradual withdrawal of the drug Barbiturate-dependent patients can be withdrawn by using a number of different withdrawal regimens. One method involves substituting a 30 mg dose of phenobarbital for each 100 to 200 mg dose of barbiturate that the patient has been taking The total daily amount of phenobarbital is then administered in 3 to 4 divided doses, not to exceed 600 mg daily.

An oral Phenobarbital (Pheno Barb) order is considered for a hospitalized patient on the Clinical Institute Withdrawal Assessment (CIWA) protocol when the patient is suspected to be physically dependent on barbiturates and is at risk of withdrawal. The dosage is determined by the patient's previous barbiturate use, with a common regimen involving 30 mg of phenobarbital for each 100 to 200 mg dose of barbiturate. The total daily dose is administered in 3 to 4 divided doses, not to exceed 600 mg daily. The goal is to gradually withdraw the patient from barbiturates while minimizing withdrawal symptoms. 2

From the Research

Oral Phenobarbital Order for Hospitalized Patients on CIWA Protocol

• The Clinical Institute Withdrawal Assessment (CIWA) protocol is used to manage alcohol withdrawal symptoms in hospitalized patients.
• Oral phenobarbital (Pheno Barb) may be considered for patients on the CIWA protocol who are at risk of severe alcohol withdrawal or have a history of seizures or delirium tremens 3, 4.
• Studies have shown that phenobarbital can be effective in reducing the severity of alcohol withdrawal symptoms and the need for intensive care unit (ICU) admission 4, 5.
• The use of phenobarbital in combination with benzodiazepines may confer some advantages in managing alcohol withdrawal symptoms, including a longer half-life and anti-glutamate activity 6, 3.
• However, the decision to use oral phenobarbital should be individualized to each patient, taking into account their medical history, severity of withdrawal symptoms, and other factors 3, 7.
• Some studies have reported that phenobarbital can be used as an adjuvant treatment for severe alcohol withdrawal, particularly in patients who are refractory to symptom-triggered benzodiazepine treatment 7.
• The choice between oral and intravenous phenobarbital should be based on the patient's clinical condition and the severity of their withdrawal symptoms, with intravenous phenobarbital preferred in more severe cases 7.