Benzobarbital

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Benzobarbital

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Method of action: Anticonvulsant

Treatment option: Hepatitis, Jaundice

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Benzobarbital

Benzobarbital is a foundational anti-epileptic medication, a synthetic barbiturate derivative designed to control the excessive electrical activity in the brain that leads to seizures. Its structure and function make it a key entity within the class of Central Nervous System (CNS) depressants, primarily administered in a tablet form for oral use.


Quick Facts

Property Description
Active ingredient Benzobarbital (beta-benzoyl-5-ethyl-5-phenylbarbituric acid)
Form Tablet (Oral)
Pharmacological class Barbiturate Derivative, Anticonvulsant
General purpose Prevention and control of seizure disorders
Origin Synthetic substance

Benzobarbital: A Synthetic Barbiturate Anticonvulsant

Benzobarbital is classified as a potent anticonvulsant belonging to the barbiturate derivative pharmacological class, used for the long-term management of convulsive disorders. It is clinically recognized for its efficacy in stabilizing electrical activity in the brain.

This medication is an entirely synthetic substance whose full chemical name is beta-benzoyl-5-ethyl-5-phenylbarbituric acid. Its classification as a CNS depressant signifies that its primary action involves globally slowing or stabilizing nerve activity, a mechanism essential for controlling the abnormal electrical discharges characteristic of seizure conditions.


Composition and Pharmaceutical Form

Benzobarbital is a single-ingredient product where the only active pharmaceutical component is Benzobarbital itself. The medicine is typically supplied as a tablet, making the most common route of administration oral.

Chemically, it is identified as an N-benzoyl derivative of Phenobarbital, a closely related barbiturate. This specific molecular structure was historically developed to potentially differentiate its pharmacological characteristics from the parent compound, supporting its specialized role in managing neurological stability.


General Purpose in Seizure Management

The general purpose of Benzobarbital is to stabilize neuronal excitability to prevent and suppress the uncontrolled electrical firing that results in convulsive episodes. A typical use scenario involves its application in chronic epilepsy management, where the goal is to provide a consistent anti-seizure effect. The drug achieves this general benefit by enhancing inhibitory neurotransmission, which provides a profound anti-excitatory effect to limit the frequency and severity of the rapid, synchronized brain activity associated with seizure disorders.

What side effects are possible with Benzobarbital?

Possible side effects and safety information for Benzobarbital

Benzobarbital is a barbiturate derivative associated with a range of possible side effects that involve the Central Nervous System, respiratory, and other systems. Most adverse reactions are an exaggeration of its known CNS depressant effects and are dose-dependent.

Frequency Common Adverse Reactions Serious Adverse Reactions
Common Drowsiness, dizziness, headache, lethargy, cognitive impairment, nausea, vomiting. Respiratory depression, physical dependence, severe withdrawal symptoms, profound sedation, severe hypotension, and life-threatening toxicity (e.g., coma) in overdose or with co-use of other CNS depressants.
Rare Hypersensitivity reactions (e.g., rash, swelling), liver toxicity, megaloblastic anemia, severe skin reactions (e.g., Stevens-Johnson syndrome).

Key Safety Considerations:

  • Dependence and Withdrawal: Prolonged use carries a significant risk of tolerance and physical dependence, and abrupt discontinuation can lead to severe withdrawal symptoms including agitation, anxiety, tremors, and seizures.
  • Drug Interactions: Benzobarbital is a potent inducer of hepatic enzymes (cytochrome P450 system), which can reduce the efficacy of co-administered medications like oral contraceptives and certain anticoagulants.
  • Contraindications: The medicine is strictly contraindicated in patients with known sensitivity to barbiturates, a history of acute porphyria, severe respiratory insufficiency, or significant hepatic impairment.
  • Population Safety: Caution is advised in older patients due to increased susceptibility to confusion and CNS depression. The drug is classified as a Pregnancy Category D medicine due to reported fetal risk, and use is generally avoided during pregnancy.

Overdose and Emergency Response

The official regulatory profile for Benzobarbital overdose centers on severe Central Nervous System (CNS) and cardiorespiratory depression. Manifestations of overdose begin with a progression of CNS effects, including severe drowsiness, confusion, ataxia, and slurred speech, which can advance rapidly to stupor and deep coma. The most serious life-threatening outcomes documented in prescribing information include severe respiratory complications, such as apnea (cessation of breathing), and cardiovascular events like profound hypotension leading to circulatory collapse and shock syndrome. These conditions require immediate intervention.


Any suspected overdose requires immediate medical attention. Regulatory documents mandate contacting emergency services or a Poison Control Center and advise that emergency and intensive care is necessary for significant intoxication. The initial response must prioritize the patient's Airway, Breathing, and Circulation (ABC). Patients with pre-existing conditions, such as Liver Disease or Congestive Heart Failure, are officially noted to be at increased risk for severe outcomes.


Treatment is defined as symptomatic and supportive therapy, as no specific antidote is described in the labeling. Supportive measures include the administration of activated charcoal and required monitoring protocols include blood tests and an Electrocardiogram (ECG) during hospitalization.

Therapeutic Uses of Benzobarbital

Quick Facts: Benzobarbital Uses

  • May support the management of seizures, including chronic epilepsy.
  • Is prescribed to address severe apprehension and agitation.
  • Is utilized for short-term support with sleep challenges.

Benzobarbital is a medication primarily prescribed to support the care of neurological conditions characterized by excessive neuronal activity. Its primary therapeutic domain is in the management of various seizure disorders, including forms of epilepsy, where it may help reduce the frequency and severity of episodes. This provides a way to help maintain control of the condition over time.

Beyond anticonvulsant applications, this medication is also used to address severe apprehension and agitation in certain clinical contexts, serving as a sedative. In limited circumstances, Benzobarbital may be prescribed for the short-term support of challenges with sleep (insomnia), where it provides a measure of temporary relief.

The overall role of Benzobarbital is to provide supportive care in these defined areas of practice.

Regulatory References

  1. NIH StatPearls therapeutic overview

Eligibility and Restrictions for Use

Official Eligibility Criteria

Regulatory agencies define strict population rules for Benzobarbital use, determining who is eligible and who is prohibited from receiving the medicine. Use is primarily established for adults and certain pediatric populations for approved indications. Eligibility is highly constrained by the patient's existing health status.

Classification Rule (Based on Regulatory Labeling)
Absolute Contraindications Prohibited in patients with severe hepatic impairment, severe respiratory insufficiency, acute intermittent porphyria, or known hypersensitivity to barbiturates.
Restricted Use Use requires caution and close monitoring for patients with renal impairment, mild to moderate hepatic impairment, and a history of substance dependence.
Age/Physiological Status The medicine is not recommended for women who are pregnant or breastfeeding. Special considerations are required for older adult (geriatric) patients due to heightened sensitivity.

What should I know about interactions with other medicines?

Benzobarbital is a barbiturate derivative and exhibits an interaction profile similar to the closely related drug phenobarbital. This profile is largely driven by its effect as a potent inducer of the liver's drug-metabolizing enzymes (Cytochrome P450 system).

Pharmacokinetic Interactions (Enzyme Induction)

Benzobarbital can significantly accelerate the metabolism of many co-administered medications, which may lead to decreased plasma concentrations and a potential loss of therapeutic effect for the interacting drug. Key categories of affected medications include:

  • Hormonal Contraceptives: Efficacy may be reduced, and non-hormonal barrier methods are generally recommended during use and for a period after discontinuation.
  • Anticoagulants: The metabolism of certain blood thinners may be increased, requiring close monitoring and dosage adjustments.
  • Other Antiepileptic Drugs: Levels of other seizure medications, such as phenytoin or carbamazepine, may be altered, which can increase side effect risk or compromise seizure control.
  • Voriconazole and Certain HIV/AIDS Treatments: Specific co-administration with strong enzyme inducers is often contraindicated due to severe risks of reduced efficacy for the antiviral or antifungal agent.

Pharmacodynamic Interactions

When Benzobarbital is combined with other substances that also cause Central Nervous System (CNS) depression, the effects are typically additive. This highly increases the risk and severity of side effects such as excessive drowsiness, dizziness, and respiratory depression. This applies to substances including alcohol, opioid pain medications, sedatives, tranquilizers, and certain antihistamines.

Contraindicated Combinations

Official regulatory information often designates combinations with other barbiturates, primidone, and voriconazole as contraindicated.

Mechanism of Action

Benzobarbital acts as a positive allosteric modulator of GABAA receptors. This interaction occurs at the receptor complex, resulting in a prolongation of the opening time of the associated chloride ion channels. The increased flux of chloride ions leads to hyperpolarization of the postsynaptic neuronal membrane. This enhanced inhibitory neurotransmission modulates the conductance properties of the neuronal membrane, primarily influencing neuronal hyperexcitability. The compound alters the phosphorylation state of specific intracellular proteins, contributing to its overall effect on GABAergic signaling. The 1-(2-ethylbutyl) group substitution at N1 influences absorption kinetics, providing a differentiated pharmacokinetic profile. Following systemic distribution, the molecule undergoes hepatic glucuronidation, producing inactive metabolites that are subsequently cleared via renal excretion. The mechanism focuses on enhancing intrinsic inhibitory signaling pathways.

Dosage and Administration Information

Benzobarbital is used for the continuous, long-term management of chronic conditions and is administered exclusively via the oral route in tablet form. The official administration protocol is structured around establishing and maintaining a stable daily dose.

Dosing and Schedule

Procedural Stage Description
Dose Initiation The regimen begins with a gradual dose adjustment (titration) from a low, initial dose.
Maintenance The medicine is taken daily in a once daily or divided dosing schedule to sustain stable plasma levels.
Administration Tablets are intended to be swallowed whole with water. The medicine may be taken with or without food.

The standard protocol requires that treatment is continuous. A critical, mandated instruction is that the medicine must never be stopped abruptly. Instead, any change in the regimen, including discontinuation, must follow a strictly slow, gradual withdrawal (tapering) schedule.

Population-Specific Use

Dosing modifications are a mandatory consideration for specific patient populations. Due to changes in metabolism and increased sensitivity, older adults require a reduced starting dose and generally use the lower end of the maintenance range. Similarly, patients with impaired hepatic or renal function require explicit dose reduction to prevent accumulation.

Recent Clinical Evidence

Research evidence / Overview of studies for Benzobarbital

This section summarizes the official research record for Benzobarbital and its pharmacological class. It focuses on the types of clinical evaluations conducted, the patient groups was evaluated in, and the specific outcomes that researchers measured for each recognized use.


Research Evidence for Managing Seizure Disorders

Benzobarbital was studied for the long-term management of seizure disorders, which are conditions characterized by fluctuating or episodic manifestations. The evidence base for this historical medication class was studied for many decades through randomized controlled trials (RCTs) and extensive observational studies. These research efforts primarily examined outcomes reflecting episodic or acute changes, such as the change in seizure frequency, the proportion of patients achieving seizure-free periods, and the time until seizure recurrence.

The large body of historical evidence for the established barbiturate class described patterns related to seizure outcome measures across medium- and long-term follow-up periods. The evidence profile relies upon by regulators reflects data collected over decades of use. Few recent, large-scale RCTs specifically examine Benzobarbital compared directly against contemporary anti-epileptic medications, meaning comparative evidence is lacking with many newer treatments.


Research Studies for Acute Stabilization and Agitation

The medication was observed in research exploring its use as a supportive agent for conditions involving periods of heightened symptoms, such as acute apprehension or systemic imbalance. Study designs included systematic reviews, meta-analyses, and retrospective cohort studies. Researchers examined outcomes monitoring physiological strain or stress, such as the control of agitation symptoms and metrics like hospital and intensive care unit (ICU) length of stay.

Systematic reviews and meta-analyses reported heterogeneous findings, meaning the findings were mixed across various studies. The trials described patterns observed in the studies related to symptom control when evaluated against other medications used in research exploring short-term symptom changes.


Research on Short-Term Support for Sleep Challenges

Benzobarbital was studied for research exploring outcomes related to difficulties falling asleep. Historical research included short-term placebo-controlled trials. Researchers examined outcomes such as change in sleep latency (the time it takes to fall asleep) and total sleep duration. Findings describe group patterns that are generally limited to very short follow-up periods, such as four weeks or less. Research scope for this use has focused only on strictly short durations, which means long-term effects are not fully established or well characterized in the research.

Key Studies & References

  1. Management of Adult Patients with Delirium in the Intensive Care Unit: An Official Clinical Practice Guideline
  2. FDA Labeling/Package Insert for Phenobarbital (Representative of Barbiturate Class Anticonvulsants)

Frequently Asked Questions (FAQ)

Common questions about Benzobarbital (FAQ)

Q: Does Benzobarbital have a high risk of dependency?

A: Yes, official drug labels for this class of medicine state there is a significant risk of tolerance and physical dependence that may occur with prolonged use, even when the medicine is taken as prescribed. For this reason, the drug is classified as a controlled substance by regulatory agencies.

Q: Can you take Benzobarbital if you have liver problems?

A: Official prescribing information states that the medicine is absolutely prohibited (contraindicated) for patients with severe hepatic impairment (serious liver problems). For those with mild to moderate liver impairment, restricted use is required, including mandatory dose reduction to prevent the medicine from accumulating in the body.

Q: Are there any common foods or drinks to avoid while using Benzobarbital?

A: Official warnings explicitly caution against consuming alcohol due to the increased risk of severe central nervous system (CNS) depression, which can cause extreme drowsiness and other serious side effects. While the medicine may be taken with or without food, no specific foods or non-alcoholic drinks are generally mentioned for avoidance in regulatory documents.

Q: Does Benzobarbital interact with hormonal birth control?

A: Yes, official documents indicate that this medicine can reduce the effectiveness of hormonal contraceptives because it causes the body to break them down faster. Regulatory documents describe that healthcare professionals may need to recommend non-hormonal barrier methods during treatment and for a period after stopping.

Q: What information should I know about Benzobarbital and kidney function?

A: Regulatory documents state that use requires caution and a mandated dose reduction for patients with renal impairment (kidney problems). This is because the medicine’s metabolites, which are the products of its breakdown, are primarily cleared by the kidneys, and reduced function could lead to accumulation.

Q: Can Benzobarbital be taken with or without food?

A: According to official administration instructions, the tablets may be taken with or without food.

Q: How quickly does Benzobarbital typically start to work?

A: As a derivative of a long-acting pharmacological class, the typical onset of action is generally one hour or longer after the tablet is swallowed. For its long-term use in managing chronic conditions, the full stabilizing effect is expected to build gradually over several days or weeks.

Q: How long does the effect of Benzobarbital usually last?

A: The drug is classified as long-acting. Official pharmacological descriptions indicate that the duration of action for a single oral dose typically lasts for 10 to 12 hours.

Q: Is Benzobarbital safe for people who drive or operate machinery?

A: Official warnings caution that this medicine may impair the mental and/or physical abilities required for performing potentially hazardous tasks like driving a car or operating machinery. Official warnings suggest that individuals determine how the medicine affects their concentration before engaging in these activities.

Q: Does Benzobarbital affect my sleep structure or quality?

A: The medicine is a central nervous system depressant and is known to alter sleep outcomes. Official warnings on the withdrawal process for this pharmacological class mention the possibility of REM rebound and disturbed sleep following abrupt discontinuation.

Q: Is it possible to develop a tolerance to Benzobarbital?

A: Yes, regulatory documents for this class state that tolerance can occur, especially following prolonged use. Tolerance means a person may need to take a higher amount of the drug over time to maintain the same effect, which is distinct from physical dependence.

Q: How long can a person typically stay on Benzobarbital?

A: The medicine is officially indicated for the long-term management of chronic conditions such as seizure disorders. This suggests that use may be continuous for an extended period, which is determined by the healthcare provider's assessment of the chronic condition.

Q: Is Benzobarbital a controlled substance in the US or other countries?

A: Yes, in the United States, Benzobarbital is classified as a Schedule IV controlled substance. This signifies that it is recognized for medical use but also carries a potential for abuse and dependence, which dictates specific storage and dispensing rules.

Q: How is the safety of Benzobarbital monitored after it's approved?

A: Safety is continuously monitored by regulatory agencies through post-marketing surveillance systems. These systems review reports of adverse events submitted by patients and healthcare professionals, helping agencies track the drug’s profile over time.

Q: Can Benzobarbital be crushed or split for easier swallowing?

A: Regulatory administration instructions state that the tablets are intended to be swallowed whole and not crushed or split, as this may interfere with the medicine's intended action and absorption.

Q: Is Benzobarbital used in children or adolescents?

A: Yes, the official eligibility criteria state that use is established for adults and certain pediatric populations for approved medical uses. However, special dosing considerations based on age and weight are mandatory due to differences in metabolism.

Q: Are there alternative treatment options similar to Benzobarbital?

A: Due to its mechanism as an anticonvulsant and CNS depressant, there are other medications in the barbiturate class and numerous contemporary anti-epileptic medications that serve similar therapeutic roles. These are listed and reviewed in official regulatory and health body guidelines.

Q: What should be included in a doctor's history before prescribing Benzobarbital?

A: Official regulatory documents indicate that the patient's history should be reviewed for all contraindications (prohibited conditions) such as severe hepatic or respiratory impairment, acute intermittent porphyria, and a history of substance dependence. These conditions prohibit or strictly restrict its use.

Q: Does Benzobarbital come in different strengths or forms?

A: The medication is primarily available in a tablet form for oral use. While a single standard form is listed, similar medicines in the same pharmacological class are regulated in multiple different strengths (e.g., 15 mg, 30 mg, etc.) to allow for dose titration.

Q: How often is Benzobarbital usually taken?

A: The medicine is taken daily as part of a continuous regimen. This regimen is typically administered either as a once daily dose or in a divided dosing schedule throughout the day to ensure stable drug levels are maintained.

Q: What is the official safety rating or classification for Benzobarbital?

A: The medicine is classified as a Pregnancy Category D drug by the FDA, indicating evidence of fetal risk. Additionally, it is classified as a Schedule IV controlled substance by the DEA.

Q: What happens if I take Benzobarbital and forget I already took it?

A: General guidance for anti-seizure medications recommends that if a dose is missed or delayed, it should be taken as soon as it is remembered. However, general guidance recommends avoiding taking a double dose at the next scheduled time; the next dose should be taken at the regular time.

Q: Do other medications need to be adjusted when starting Benzobarbital?

A: Yes, regulatory documents indicate that because Benzobarbital is a potent enzyme inducer, the dose of certain co-administered medications like anticoagulants (blood thinners) may need to be adjusted by a healthcare professional, requiring close monitoring.

Q: Is Benzobarbital mainly used for short-term or long-term issues?

A: Its primary use, as stated in regulatory documents, is for the long-term management of chronic conditions such as seizure disorders. However, the medicine has also been historically studied for short-term support for other issues, such as sleep challenges.

Q: Does taking Benzobarbital prevent me from getting certain vaccines?

A: There is limited official information in regulatory documents on direct interactions between this medicine and vaccines. However, some evidence suggests that certain vaccines may potentially alter the metabolism of anti-epileptic drugs, which could affect the level of the medicine in the body.

Q: Is it possible to be allergic to the ingredients in Benzobarbital?

A: Yes, official safety information states the medicine is strictly contraindicated (prohibited) in patients with known hypersensitivity to barbiturates or any of its inactive ingredients, as an allergic-type reaction is possible.

Q: What is the risk of overdose with Benzobarbital?

A: Official warnings state that an overdose can lead to life-threatening toxicity, including profound sedation, severe hypotension (very low blood pressure), and coma. The risk of toxicity is significantly increased when the medicine is taken with other Central Nervous System depressants.

Q: Can Benzobarbital affect my mood or behavior?

A: Yes, official side effect information for this class of medicine includes reactions such as excitement or increased activity (which is sometimes seen in children), confusion, and other forms of cognitive impairment, which are all changes to mood or mental state.

Q: Can Benzobarbital cause problems with memory?

A: Yes, official safety information lists cognitive impairment as a common adverse reaction of this medicine. This category of side effects can include issues with concentration, thinking, and memory.

Q: Are there any long-term health risks associated with Benzobarbital?

A: Long-term use is primarily associated with the risk of developing physical dependence and tolerance. Regulatory documents emphasize that because the medicine is used continuously, any change or discontinuation of the regimen must be done strictly and slowly to mitigate the risk of severe withdrawal symptoms.

How should Benzobarbital be stored and disposed of?

Benzobarbital tablets must be stored at Controlled Room Temperature, which is defined by regulatory agencies as 20 C to 25 C (68 F to 77 F). The medication must be protected from light and moisture to ensure its stability.

Requirement Official Regulatory Mandate
Container Dispense in a tight, light-resistant container with a child-resistant closure.
Child Safety Must be stored out of the reach and sight of children.
Disposal Disposal should prioritize drug take-back programs. If unavailable, mix the tablets with an unappealing substance (e.g., used coffee grounds) and place in a sealed container before discarding in the household trash.
Environmental Rule Do not flush the unused medication down the toilet or sink.

Storage must comply with all federal and state regulations for a Schedule IV controlled substance.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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