Phenobarbital
Rx Only
Generic NamePhenobarbital
Therapeutic ClassBarbiturate / Anticonvulsant
Common Dose30–120 mg/day in 1–2 divided doses
Max / 24h400 mg
PregnancyCategory D
Indications ▼
Generalized tonic-clonic and partial seizures
Status epilepticus (short-term IV therapy)
Febrile seizures in children (selected cases)
Preoperative sedation
Insomnia (short-term use, rarely)
Mechanism & Pharmacokinetics ▼
Mechanism: Enhances GABA-mediated chloride influx, leading to CNS depression, anticonvulsant and sedative effects.
Pharmacokinetics: Well absorbed orally, onset 20–60 min. Half-life ~80–120 hours in adults. Hepatic metabolism; excreted renally. Long-acting barbiturate suitable for once-daily dosing in seizure prophylaxis.
Dosage & Administration ▼
| Patient Category | Recommended Dose | Max / 24h |
|---|---|---|
| Adults | 60–120 mg/day orally in 1–2 divided doses | 400 mg |
| Children (1 month – 12 yrs) | 3–5 mg/kg/day orally in 1–2 divided doses | 200 mg |
| Neonates | 5–8 mg/kg/day orally or IV/IM in divided doses | Max 20 mg/kg/day |
| Elderly | Start at lower dose; monitor sedation and respiratory function | 200 mg |
Note: Administer orally or IV slowly. Monitor for respiratory depression, sedation, and CNS effects. Adjust dose in hepatic or renal impairment.
Side Effects ▼
Common: Sedation, dizziness, ataxia, cognitive impairment
Occasional: Nausea, hypotension, rash
Serious: Respiratory depression, hepatotoxicity, dependence, withdrawal seizures
Contraindications ▼
Hypersensitivity to barbiturates
Severe respiratory insufficiency
Porphyria
History of addiction or substance abuse
Drug Interaction ▼
CNS depressants: additive sedation
Oral anticoagulants: may alter metabolism
Contraceptives: reduced efficacy
Other anticonvulsants: adjust doses as needed
Pregnancy & Lactation ▼
Category D – risk of fetal malformations
Use only if benefits outweigh risks
Excreted in breast milk; monitor infant for sedation
Clinical / Research Summary ▼
Effective long-term prophylaxis in generalized tonic-clonic and partial seizures.
Reduces seizure frequency but requires careful monitoring for sedation and dependence.
Used in neonatal seizures due to long half-life and predictable pharmacokinetics.
Patient Counseling Points ▼
Take exactly as prescribed; do not discontinue abruptly.
Avoid alcohol and CNS depressants.
Report excessive drowsiness, confusion, or respiratory issues immediately.
Storage & Handling ▼
Store at 20–25°C; protect from light and moisture
Keep out of reach of children
Brand Names (Bangladesh & Global) ▼
Bangladesh:
Barbit® 30 mg Tablet
Barbit® 60 mg Tablet
Barbit Elixir® 20 mg/5 ml
Barbit® 200 mg/ml Injection
Emer® 30 mg Tablet
Emer® 60 mg Tablet
Emer® 20 mg/5 ml Syrup
Emer® 200 mg/ml Injection
G‑Phenobarbitone® 30 mg Tablet
G‑Phenobarbitone® 200 mg/ml Injection
Phenobarbitone® 30 mg Tablet
Phenoson® 30 mg Tablet
Global:
Medical Disclaimer: This information is for educational purposes only and should not replace professional medical advice. Always consult a qualified healthcare provider.
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