Generic Name
Phenobarbital
Group
Barbiturate, Antiepileptic, Sedative-hypnotic
Mechanism of Action
Enhances GABA-mediated chloride influx at GABAA receptors, increasing inhibitory neurotransmission and reducing neuronal excitability.
Indications
- Generalized tonic-clonic seizures
- Partial seizures
- Neonatal seizures
- Status epilepticus (alternative when other drugs unavailable)
- Occasionally used as sedative/hypnotic
Dose
- Adults (epilepsy): 60–200 mg/day orally in divided doses.
- Children: 3–5 mg/kg/day orally in 1–2 divided doses.
- Neonates: Loading dose 15–20 mg/kg IV, then 3–4 mg/kg/day orally or IV.
Major Side Effects
- Drowsiness, sedation
- Ataxia, cognitive impairment
- Dependence and withdrawal symptoms
- Respiratory depression (at high doses)
- Hypotension (IV use)
Contraindications
- Hypersensitivity to barbiturates
- Severe respiratory depression
- Severe hepatic impairment
- History of porphyria
Compatible Fluid
- Normal saline (NS)
- Not compatible with dextrose solutions (precipitation may occur)
Route of Administration
- Oral (tablet, elixir)
- Intravenous (IV)
- Intramuscular (IM)
Type of Administration
Chronic maintenance therapy for seizures; can also be used acutely for neonatal seizures or status epilepticus (when other drugs are not available).