Therapeutic Classification: anticonvulsants
Absorption: Completely absorbed following oral administration.
Distribution: Enters breast milk, remainder of distribution unknown.
Metabolism/Excretion: Minimal metabolism, mostly eliminated unchanged in urine.
Half-Life: 7.5 hr.
- Either tablets or powder for oral solution can be used for refractory complex partial seizures; only powder for oral solution should be used for infantile spasms.
Refractory Complex Partial Seizures
- PO (Adults and Children ≥17 yr): 500 mg twice daily initially; may ↑ in 500-mg increments every 7 days, depending on response, up to 1500 mg twice daily.
- PO (Children 216 yr and >60 kg): 500 mg twice daily initially; may ↑ in 500-mg increments every 7 days, depending on response, up to 1500 mg twice daily.
- PO (Children 216 yr and 2660 kg): 250 mg twice daily initially; may ↑ every 7 days, depending on response, up to 1000 mg twice daily.
- PO (Children 216 yr and 2125 kg): 250 mg twice daily initially; may ↑ every 7 days, depending on response, up to 750 mg twice daily.
- PO (Children 216 yr and 1620 kg): 225 mg twice daily initially; may ↑ every 7 days, depending on response, up to 650 mg twice daily.
- PO (Children 216 yr and 1015 kg): 175 mg twice daily initially; may ↑ every 7 days, depending on response, up to 525 mg twice daily.
Renal Impairment
- PO (Adults and Children ≥2 yr and ≥10 kg): CCr >5080 mL/min: ↓dose by 25%; CCr >3050 mL/min: ↓dose by 50%; CCr >1030 mL/min: ↓dose by 75%.
Infantile Spasms
- PO (Children 1 mo2 yr): 25 mg/kg twice daily initially; may be ↑ by 2550 mg/kg/day increments every 3 days up to a maximum of 150 mg/kg/day (75 mg/kg twice daily); dosage adjustments are necessary for renal impairment.