Tablets
50 mg
100 mg
Injection
50 mg/ml
Dosage Forms
Uses
Dose and Duration
Grand mal epilepsy
Adult: Initially, 3–4 mg/kg (150–300 mg) daily as single dose or 2 divided doses. Increase gradually at intervals of 2 weeks as necessary to usually 200–500 mg daily
Child: Initially, 3–5 mg/kg daily in 2 divided doses. Increased gradually according to clinical response to a usual maintenance dose of 4–8 mg/kg daily (max 300 mg daily)
Status epilepticus
Adult and child over 12 years: by slow IV injection or IV infusion, 15 mg/kg at a rate not more than 50 mg/minute as loading dose. Maintenance dose of 100 mg by mouth or slow intravenous infusion every 6–8 hours
Child 1 month–12 years: 20 mg/kg as a loading dose at a rate of 1 mg/kg/minute (max 50 mg/minute). Maintenance dose of 2.5–5 mg/kg every 12 hours
Neonate: 20 mg/kg as a loading dose at rate of 1–3 mg/kg/minute. Maintenance dose of up to 100 mg every 6–8 hours
Neuropathic pain
Adult: 200–400 mg daily in 1–2 divided doses. Up to 600 mg daily may be needed