Section 13 · Monograph
Pentobarbital
Reviewed Nov 2026FDA label
NembutalBarbiturate
- Forms
- IV/IM: 50mg/mL
- Dose
- Refractory status epilepticus or ICP coma (off-label): load 5-15mg/kg IV (max 50mg/min), then 0.5-5mg/kg/h titrated to EEG burst suppression
- MOA
- ↑GABA-A Cl- channel open duration
Indications
- Sedative; short-term treatment of insomniaFDA-labeled
- PreanestheticFDA-labeled
- Anticonvulsant in anesthetic doses for emergency control of acute convulsive episodes (status epilepticus, tetanus, eclampsia)FDA-labeled
Off-Label Uses
- Refractory status epilepticus (barbiturate coma)Off-label
- Refractory intracranial hypertension (barbiturate coma)Off-label
Mechanism of Action
- Barbiturate that prolongs GABA-A chloride channel opening and, at high concentrations, directly activates the channel and inhibits glutamate; lowers cerebral metabolic rate and ICP
Full Dosing
Adult / usual
- Refractory status epilepticus or ICP coma (off-label): loading dose 5-15mg/kg IV at no faster than 50mg/min, then infusion 0.5-5mg/kg/h titrated to EEG burst suppression
- Requires intubation, mechanical ventilation, continuous EEG and vasopressor readiness
- Taper slowly after seizure control or ICP resolution
Contraindications
- Hypersensitivity to barbiturates
- Porphyria
- Marked liver impairment; severe respiratory disease with dyspnea or obstruction
Drug Interactions
- Induces CYP enzymes (reduces warfarin, hormonal contraceptives, many AEDs)
- Additive CNS and respiratory depression with benzodiazepines, opioids and alcohol
- Valproate raises barbiturate levels
Adverse Effects
- Profound hypotension requiring vasopressors
- Respiratory depression
- Prolonged sedation and slow recovery (long half-life)
- Ileus, immunosuppression and infections
- Propylene glycol/ethanol vehicle toxicity with large doses
Monitoring Parameters
- Continuous EEG and hemodynamics
- Serum level, osmolar gap and lactate
- Infection surveillance and bowel function
Pregnancy & Lactation
- Fetal harm and neonatal withdrawal/hemorrhage risk; use only when necessary
- Excreted in milk