Therapeutic Classification: anticonvulsants
Pharmacologic Classification: pyrrolidines
Absorption: Rapidly and completely absorbed following oral administration. IV administration results in complete bioavailability.
Distribution: Well distributed to tissues.
Metabolism/Excretion: 66% excreted unchanged by the kidneys; some metabolism by the liver (metabolites inactive).
Half-Life: 7.1 hr (↑ in renal impairment).
- Only the oral solution should be used in patients ≤20 kg.
Partial Onset Seizures
- PO IV (Adults and Children ≥16 yr): 500 mg twice daily initially; may ↑ by 1000 mg/day at 2-wk intervals up to 3000 mg/day in 2 divided doses.
- PO (Adults and Children 4–15 yr): Oral solution: 10 mg/kg twice daily; ↑ by 20 mg/kg/day at 2-wk intervals to recommended dose of 30 mg/kg twice daily (not to exceed 1500 mg twice daily). Immediate-release tablets or tablets for oral suspension (for patients >40 kg): 500 mg twice daily; may ↑ by 1000 mg/day at 2-wk intervals up to 3000 mg/day in 2 divided doses. Immediate-release tablets or tablets for oral suspension (for patients 20–40 kg): 250 mg twice daily; may ↑ by 500 mg/day at 2-wk intervals up to 1500 mg/day in 2 divided doses.
- PO (Adults and Children ≥12 yr and ≥50 kg): Extended release: 1000 mg once daily; may ↑ by 1000 mg/day at 2-wk intervals up to 3000 mg once daily.
- IV (Children 4–15 yr): 10 mg/kg twice daily; ↑ by 20 mg/kg/day at 2-wk intervals to recommended dose of 30 mg/kg twice daily (not to exceed 1500 mg twice daily).
- PO IV (Children 6 mo–3 yr): 10 mg/kg twice daily; ↑ by 20 mg/kg/day at 2-wk intervals to recommended dose of 25 mg/kg twice daily.
- PO IV (Children 1–5 mo): 7 mg/kg twice daily; ↑ by 14 mg/kg/day at 2-wk intervals to recommended dose of 21 mg/kg twice daily.
Renal Impairment
- PO IV (Adults ): CCr 50–80 mL/min: 500–1000 mg twice daily (1000–2000 mg once daily for extended release); CCr 30–50 mL/min: 250–750 mg twice daily (500–1500 mg once daily for extended release); CCr <30 mL/min: 250–500 mg twice daily (500–1000 mg once daily for extended release); Dialysis (immediate release and injection): 500–1000 mg once daily with a 250–500-mg supplemental dose after dialysis.
Primary Generalized Tonic-Clonic Seizures
- PO IV (Adults and Children ≥16 yr): 500 mg twice daily initially; ↑ by 1000 mg/day at 2-wk intervals to recommended dose of 3000 mg/day.
- PO (Adults and Children ≥6 yr and >40 kg): Tablets for oral suspension: 500 mg twice daily; may ↑ by 1000 mg/day at 2-wk intervals up to 3000 mg/day in 2 divided doses.
- PO IV (Children 6–15 yr): 10 mg/kg twice daily; ↑ by 20 mg/kg/day at 2-wk intervals to recommended dose of 30 mg/kg twice daily.
- PO (Children ≥6 yr and 20–40 kg): Tablets for oral suspension: 250 mg twice daily; may ↑ by 500 mg/day at 2-wk intervals up to 1500 mg/day in 2 divided doses.
Renal Impairment
- PO IV (Adults ): CCr 50–80 mL/min (immediate release and injection): 500–1000 mg twice daily; CCr 30–50 mL/min (immediate release and injection): 250–750 mg twice daily; CCr <30 mL/min (immediate release and injection): 250–500 mg twice daily; Dialysis (immediate release and injection): 500–1000 mg once daily with a 250–500-mg supplemental dose after dialysis.
Myoclonic Seizures
- PO IV (Adults and Children ≥12 yr): 500 mg twice daily initially; ↑ by 1000 mg/day at 2-wk intervals to recommended dose of 3000 mg/day (in 2 divided doses).
Renal Impairment
- PO IV (Adults ): CCr 50–80 mL/min (immediate release and injection): 500–1000 mg twice daily; CCr 30–50 mL/min (immediate release and injection): 250–750 mg twice daily; CCr <30 mL/min (immediate release and injection): 250–500 mg twice daily; Dialysis (immediate release and injection): 500–1000 mg once daily with a 250–500-mg supplemental dose after dialysis.
Status Epilepticus
- IV (Infants and Children <16 yr): 50 mg/kg as a loading dose followed by maintenance dose of 30–55 mg/kg/day IV/PO in 2 divided doses.
- IV (Neonates ): 20–30 mg/kg as a loading dose followed by neonatal seizure dosing.
