Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
BUTABARB vs BREVITAL SODIUM
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Barbiturate that binds to GABA-A receptor subunits, potentiating GABAergic inhibition by increasing chloride ion conductance and reducing neuronal excitability.
Brevital sodium (methohexital) is a barbiturate that acts as a GABA-A receptor agonist, enhancing chloride ion influx and hyperpolarizing neurons, leading to rapid sedation and anesthesia.
Sedative,Hypnotic,Anticonvulsant,Preoperative anxiety
Induction and maintenance of general anesthesia,Adjunct to regional anesthesia,Short-duration surgical procedures
15-30 mg orally 3-4 times daily as needed; maximum 200 mg/day. IV/IM: 50-200 mg for sedation.
Induction of anesthesia: 1-1.5 mg/kg IV bolus over 15 seconds; maintenance: 0.5-1 mg/kg IV bolus as needed or 50-150 mcg/kg/min IV infusion.
Terminal elimination half-life is 30-60 hours (mean ~40 hours) in adults with normal renal and hepatic function. Longer in elderly or patients with liver disease.
Terminal elimination half-life: 3–6 hours (mean ~4 hours); prolonged in hepatic impairment, obesity, or with repeated dosing due to redistribution.
Hepatic metabolism via CYP2C9 and CYP2C19; minor pathways involve glucuronidation.
Hepatic metabolism primarily by CYP2C9 and CYP3A4 to inactive metabolites; less than 1% excreted unchanged in urine.
Renal excretion of unchanged drug and metabolites. Approximately 70-80% of a dose is eliminated in urine as metabolites (hydroxy and glucuronide conjugates) and <5% as parent drug. Minimal biliary/fecal elimination (<5%).
Primarily hepatic biotransformation to inactive metabolites (mainly hydroxy-methohexital), with renal excretion of metabolites; less than 1% excreted unchanged in urine. Minor biliary/fecal elimination.
Approximately 20-25% bound to plasma proteins (albumin).
Approximately 70–90% bound to albumin.
0.5-0.6 L/kg in adults. Higher Vd suggests distribution into total body water and tissues; may increase in obesity.
Vd: 1.1–2.5 L/kg (mean ~1.5 L/kg). Larger Vd indicates extensive tissue distribution (highly lipophilic), leading to rapid redistribution and short duration after single bolus.
Oral: 95-100% (well absorbed). Rectal: 80-90%. IM: 80-100%.
IV: 100%. IM: Not well established; likely >90%. Rectal: Variable, ~50–70% due to first-pass metabolism and incomplete absorption.
e GFR 30-50 m L/min: reduce dose by 25%. e GFR <30 m L/min: avoid use or use 50% reduction with caution.
No dosage adjustment required for GFR ≥10 m L/min; for GFR <10 m L/min, reduce dose by 50%.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: contraindicated.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: reduce dose by 75% or consider alternative.
0.5-1 mg/kg/dose orally every 6-8 hours; maximum 30 mg/dose. Not recommended for children under 6 years.
Induction: 1-2 mg/kg IV; maintenance: 0.5-1 mg/kg IV bolus or 50-150 mcg/kg/min IV infusion. Contraindicated in infants <2 months with stable BSA.
Initiate at 7.5-15 mg orally 2-3 times daily; increase slowly. Avoid in frail elderly. Monitor for paradoxical excitation.
Reduce induction dose by 50% and administer slowly over 60 seconds; maintenance infusion rates at lower end (50-100 mcg/kg/min).
May be habit forming; potential for abuse and dependence. Abrupt discontinuation may precipitate life-threatening withdrawal symptoms.
None.
Respiratory depression, especially when combined with other CNS depressants; tolerance and dependence; withdrawal seizures; use with caution in hepatic impairment and elderly.
Respiratory depression and apnea may occur; resuscitative equipment must be available,Hypotension and bradycardia possible; use with caution in patients with cardiovascular disease,Extravasation causes tissue necrosis; avoid intra-arterial injection,Seizures may occur in epileptic patients,Rapid injection may cause severe respiratory depression
Hypersensitivity to barbiturates, porphyria, severe respiratory insufficiency, history of substance abuse.
Known hypersensitivity to barbiturates,Porphyria (may precipitate acute attacks),Severe respiratory insufficiency,Status asthmaticus,Hypovolemic shock or severe hypotension
Avoid grapefruit juice as it may inhibit metabolism and increase sedative effects. Take with food if gastrointestinal upset occurs. Limit caffeine intake as it may reduce sedative efficacy.
No specific food interactions are documented for BREVITAL SODIUM. However, patients should avoid heavy meals before anesthesia due to risk of aspiration. Do not consume alcohol or grapefruit juice for 24 hours before and after administration, as they may alter drug metabolism and increase sedation.
Butabarbital is a barbiturate classified as FDA Pregnancy Category D. First trimester: Increased risk of congenital malformations, particularly oral clefts, neural tube defects, and cardiovascular anomalies. Second and third trimesters: Potential for fetal dependence, withdrawal syndrome, and impaired brain development. Chronic use may cause fetal growth restriction and preterm birth.
Teratogenic potential not fully established in humans. In animal studies, methohexital caused fetal resorptions and malformations at maternally toxic doses. First trimester: Avoid unless essential; risk of neural tube defects cannot be excluded. Second trimester: Limited data, but may cause fetal depression if used near delivery. Third trimester: Crosses placenta; may cause neonatal respiratory depression, hypotonia, and prolonged sedation. Use only if clearly needed with lowest effective dose.
Barbiturates are excreted into breast milk in low concentrations. M/P ratio is approximately 0.5-0.6. Chronic high-dose use may lead to infant sedation and difficulty feeding. Monitor infant for signs of drowsiness, lethargy, or poor suckling. Use caution, especially in neonates or preterm infants.
Excretion into human milk unknown. M/P ratio not determined. Due to short half-life, minimal transfer expected after a single dose. Caution with repeated doses or prolonged infusion. Monitor infant for sedation, feeding difficulties, or respiratory depression.
Pregnancy induces hepatic microsomal enzymes, increasing barbiturate metabolism. Higher doses (increased by 30-50%) may be required to maintain therapeutic levels. Monitor serum drug levels if needed, especially in third trimester. Postpartum, reduce dose to prepregnancy levels to avoid toxicity.
Pregnancy may increase volume of distribution and clearance, potentially requiring higher initial doses, but the induction dose typically unchanged. Reduced doses may be needed in preeclampsia or cesarean section due to enhanced sensitivity. No specific dose adjustment guidelines; titrate to effect with careful monitoring.
Butabarbital is a short-acting barbiturate with a rapid onset; monitor for respiratory depression, especially when combined with other CNS depressants. Use with caution in hepatic impairment due to prolonged half-life. Tolerance and dependence develop with prolonged use; abrupt discontinuation may precipitate withdrawal seizures. Barbiturates induce CYP450 enzymes, potentially reducing efficacy of oral contraceptives, warfarin, and corticosteroids.
BREVITAL SODIUM (methohexital) is an ultrashort-acting barbiturate used for induction of anesthesia and for short procedures. Due to its rapid onset and brief duration, it requires careful titration. It is contraindicated in patients with porphyria. Extravasation causes tissue necrosis; administer only through a secure IV line. It lowers seizure threshold, but can also be used for electroconvulsive therapy (ECT) to induce seizures. Respiratory depression and hypotension are dose-dependent; have resuscitation equipment ready. Avoid in patients with severe hepatic impairment. Coadministration with opioids or benzodiazepines potentiates sedation and respiratory depression.
Take exactly as prescribed; do not increase dose or frequency without consulting your doctor.,Avoid alcohol and other CNS depressants (e.g., benzodiazepines, opioids) as they may cause severe sedation or respiratory depression.,Do not drive or operate heavy machinery until you know how this medication affects you.,Do not stop taking abruptly; withdrawal can cause anxiety, tremors, and seizures. Taper under medical supervision.,This medication may be habit-forming; store in a safe place to prevent misuse.,Notify your doctor if you are pregnant, planning to become pregnant, or breastfeeding.,Inform your doctor of all medications you take, including herbal supplements and over-the-counter drugs.
BREVITAL SODIUM is a potent anesthetic that causes rapid loss of consciousness and should only be administered by trained medical professionals.,You may experience temporary pain or burning at the injection site; report any persistent pain or swelling to your healthcare provider.,Drowsiness, dizziness, and confusion may persist for several hours after the procedure; do not drive or operate machinery for at least 24 hours.,Avoid alcohol and other sedatives for 24 hours before and after the procedure as they may increase side effects.,Inform your doctor if you have a history of porphyria, liver disease, or drug allergies.,If you are pregnant or breastfeeding, discuss the risks and benefits with your healthcare provider.
"Butabarbital, a barbiturate, induces cytochrome P450 (CYP) enzymes, enhancing the hepatic metabolism of ketamine, a dissociative anesthetic primarily metabolized by CYP3A4 and CYP2B6. This interaction reduces ketamine's systemic exposure and anesthetic efficacy, potentially leading to suboptimal sedation or anesthesia. Additionally, concurrent use may increase the risk of respiratory depression and hypotension due to additive central nervous system (CNS) depressant effects."
"Butabarbital, a barbiturate, is a potent CNS depressant that acts primarily by potentiating GABA-A receptor activity. Metaxalone is a centrally acting muscle relaxant with sedative properties. Coadministration results in additive or synergistic CNS depression, leading to increased risk of excessive sedation, respiratory depression, impaired psychomotor function, and potential coma or death, especially at higher doses or in vulnerable patients."
"Butabarbital, a barbiturate sedative-hypnotic, induces hepatic cytochrome P450 enzymes, particularly CYP3A4, which are responsible for metabolizing the atypical antipsychotic paliperidone. This induction decreases plasma concentrations of paliperidone, potentially reducing its therapeutic efficacy in treating schizophrenia or bipolar disorder. Concomitant use may lead to relapse of psychiatric symptoms or necessitate dose adjustments."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about BUTABARB vs BREVITAL SODIUM, answered by our medical review team.
BUTABARB is a Barbiturate that works by Barbiturate that binds to GABA-A receptor subunits, potentiating GABAergic inhibition by increasing chloride ion conductance and reducing neuronal excitability.. BREVITAL SODIUM is a Barbiturate Anesthetic that works by Brevital sodium (methohexital) is a barbiturate that acts as a GABA-A receptor agonist, enhancing chloride ion influx and hyperpolarizing neurons, leading to rapid sedation and anesthesia.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between BUTABARB and BREVITAL SODIUM depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of BUTABARB is: 15-30 mg orally 3-4 times daily as needed; maximum 200 mg/day. IV/IM: 50-200 mg for sedation.. The standard adult dose of BREVITAL SODIUM is: Induction of anesthesia: 1-1.5 mg/kg IV bolus over 15 seconds; maintenance: 0.5-1 mg/kg IV bolus as needed or 50-150 mcg/kg/min IV infusion.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between BUTABARB and BREVITAL SODIUM in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. BUTABARB is classified as Category C. Butabarbital is a barbiturate classified as FDA Pregnancy Category D. First trimester: Increased risk of congenital malformations, particularly oral clefts, neural tube defects, an. BREVITAL SODIUM is classified as Category C. Teratogenic potential not fully established in humans. In animal studies, methohexital caused fetal resorptions and malformations at maternally toxic doses. First trimester: Avoid . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.