Ethosuximide

Administration

  • Type: Anticonvulsant
  • Dosage Forms: 250; 250/5mL
  • Routes of Administration: oral tablet, oral syrup
  • Common Trade Names: Zarontin

Adult Dosing

Seizure, absence

  • Start: 250mg PO bid
    • May increase 250mg/day q4-7 days
    • Taper dose based on tx response to D/C
  • Max: 1.5 g/day

Pediatric Dosing

Seizure, absence

  • 3-6 yo
    • 20 mg/kg/day PO divided bid
      • Start: 250 mg PO QD
      • Max: 1.5 g/day
      • Taper dose based on tx response to D/C
  • 6+ yo
    • 20 mg/kg/day PO divided bid
      • Start: 250 mg PO QD
      • Max: 1.5 g/day
      • Taper dose based on tx response to D/C

Special Populations

Renal Dosing

  • Adult:
    • CrCl <10: Decrease dose 25%
    • HD: Give after dialysis
    • PD: No adjustment
  • Pediatric:
    • CrCl <10: Decrease dose 25%
    • HD: Give after dialysis
    • PD: No adjustment

Hepatic Dosing

  • Adult: Not defined
  • Pediatric: Not defined

Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

Common

Pharmacology

  • Half-life: 56-60 hr
  • Metabolism: Liver extensively; CYP450: 3A4 substrate
  • Excretion: Urine primarily (<20% unchanged), bile/feces

Mechanism of Action

  • Depresses motor cortex
  • Elevates CNS convulsive stimuli threshold

Comments

See Also

References