BUTABARBITAL SODIUM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for BUTABARBITAL SODIUM (BUTABARBITAL SODIUM).
Depresses neuronal activity in the reticular activating system by enhancing GABA-A receptor-mediated chloride influx, increasing the duration of chloride channel opening and inhibiting excitatory neurotransmission at high doses.
| Metabolism | Primarily hepatic via CYP2C9, CYP2C19, and CYP3A4; conjugated with glucuronic acid; excreted renally. |
| Excretion | Renal: 50-70% as metabolites (hydroxylated and conjugated forms), 5-10% unchanged; fecal: minor (<5%) |
| Half-life | Terminal elimination half-life: 30-50 hours; accumulates with repeated dosing, prolonged in hepatic impairment |
| Protein binding | 25-35%, primarily to albumin |
| Volume of Distribution | 0.5-0.8 L/kg; distributes widely into tissues, crosses blood-brain barrier |
| Bioavailability | Oral: 80-100% (rapid absorption); IM: complete |
| Onset of Action | Oral: 30-60 minutes; IM: 10-30 minutes; IV: 1-5 minutes |
| Duration of Action | Oral/IM: 6-8 hours; IV: 4-6 hours; effects may be prolonged in hepatic disease |
Sedative: 15-30 mg orally 3-4 times daily. Hypnotic: 50-100 mg orally at bedtime. Maximum single dose: 100 mg. Maximum daily dose: 300 mg. Route: oral, intramuscular, intravenous. For IM/IV: divide oral dose by 2.
| Dosage form | TABLET |
| Renal impairment | Contraindicated in severe renal impairment (eGFR <30 mL/min). For eGFR 30-50 mL/min: reduce dose by 25% and monitor for CNS depression. eGFR >50 mL/min: no adjustment. |
| Liver impairment | Contraindicated in Child-Pugh Class C. Child-Pugh A: reduce dose by 50%. Child-Pugh B: reduce dose by 75% or use alternative. Avoid in severe hepatic impairment. |
| Pediatric use | Not recommended for children <6 years. For children 6-12 years: sedative 5-15 mg orally 3-4 times daily; hypnotic not typically used. For adolescents >12 years: adult dosing with caution. Maximum single dose: 30 mg. Weight-based: 2-3 mg/kg/day divided every 6-8 hours, not to exceed 100 mg/day. |
| Geriatric use | Start with lowest effective dose (e.g., 15 mg orally for sedation). Maximum dose: 50 mg per dose. Caution due to increased sensitivity, risk of falls, and cognitive impairment. Avoid hypnotic use. Consider non-barbiturate alternatives. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for BUTABARBITAL SODIUM (BUTABARBITAL SODIUM).
| Breastfeeding | Excreted in breast milk; M/P ratio estimated 0.3-0.5. Risk of infant sedation, poor feeding, and withdrawal. Contraindicated in breastfeeding unless essential. Monitor for drowsiness, weight gain, and developmental milestones. |
| Teratogenic Risk | First trimester: Increased risk of major malformations, particularly oral clefts (odds ratio 2.0-3.0). Second trimester: Risk of neural tube defects and cardiac anomalies. Third trimester: Neonatal withdrawal syndrome, respiratory depression, and hemorrhagic disease due to vitamin K deficiency. FDA Category D. |
■ FDA Black Box Warning
Barbiturates are habit-forming. Tolerance, psychological and physical dependence may occur. Withdrawal symptoms include delirium, convulsions, and death. Abrupt cessation after prolonged use is not recommended.
| Common Effects | Nausea Vomiting Stomach pain epigastric pain Heartburn Diarrhea Loss of appetite |
| Serious Effects |
Hypersensitivity to barbiturates, porphyria, severe respiratory disease, severe hepatic impairment, history of addiction to sedative-hypnotics.
| Precautions | Respiratory depression risk; use caution in hepatic impairment, renal impairment, elderly, or debilitated patients; avoid abrupt discontinuation; may cause paradoxical excitement; monitor for hypersensitivity reactions. |
| Food/Dietary | Avoid grapefruit juice as it may alter metabolism. Limit or avoid alcohol; concurrent use increases CNS depression risk. Take with food if GI upset occurs; avoid high-fat meals as they may slow absorption. |
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| Fetal Monitoring |
| Maternal: Plasma barbiturate levels, LFTs, coagulation profile (PT/INR), and CBC. Fetal: Ultrasound for anatomy and growth, nonstress test, and biophysical profile in third trimester. Neonatal: Observe for withdrawal (irritability, tremors, seizures) for 72 hours postpartum. |
| Fertility Effects | No direct evidence of impaired fertility. May disrupt menstrual cyclicity via hepatic enzyme induction affecting sex hormone metabolism. Use with caution in women attempting conception. |
| Clinical Pearls | Barbiturate with rapid onset used for preoperative sedation and seizure control. Respiratory and CNS depression risk is dose-dependent; avoid in porphyria. Tolerance develops with prolonged use; withdrawal can be life-threatening. Use as second-line for status epilepticus after benzodiazepines. Highly protein-bound; monitor for interactions with warfarin and oral contraceptives. |
| Patient Advice | Take exactly as prescribed; do not increase dose or frequency. · Avoid alcohol and other CNS depressants (e.g., opioids, benzodiazepines). · Do not drive or operate machinery until you know how this drug affects you. · Do not stop suddenly; abrupt discontinuation can cause withdrawal seizures. · Inform your doctor if you have a history of porphyria, liver disease, or depression. · Use effective contraception; this drug may reduce hormonal contraceptive efficacy. |