Absorption: Well absorbed (80%) after oral administration.
Distribution: Unknown.
Metabolism/Excretion: 70% excreted unchanged in urine.
Half-life: 21 hr; Extended-release 31 hr.
Derm: STEVENS-JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS, oligohydrosis (↑ in children).
EENT: abnormal vision, diplopia, nystagmus, acute myopia/secondary angle closure glaucoma, ↑ intraocular pressure, mydriasis, ocular pain, ocular redness, retinal detachment, visual field defects.
F and E: hyperchloremic metabolic acidosis.
GI: nausea, abdominal pain, anorexia, constipation, dry mouth, encephalopathy, hyperammonemia.
GU: kidney stones.
Hemat: BLEEDING, leukopenia.
Metab: weight loss, hyperthermia (↑ in children).
Neuro: ataxia, paresthesia, tremor , SEIZURES, SUICIDAL THOUGHTS, cognitive disorders, dizziness, drowsiness, fatigue, impaired concentration/memory, nervousness, psychomotor slowing, speech problems, sedation, aggressive reaction, agitation, anxiety, confusion, depression, malaise, mood problems.
Misc: fever.

Epilepsy (monotherapy)
- PO (Adults and Children
10 yr): Immediate-release 25 mg twice daily initially, gradually ↑ at weekly intervals to 200 mg twice daily over a 6wk period; Extended-release (Qudexy XR or Trokendi XR) 50 mg once daily initially, gradually ↑ at weekly intervals to 400 mg once daily over a 6wk period. - PO (Children 2<10 yr [6<10 yr for Trokendi XR] and >38 kg): Immediate-release 25 mg once daily in the evening initially, gradually ↑ at weekly intervals to 125 mg twice daily over a 57-wk period; if needed may continue to titrate dose on a weekly basis up to 200 mg twice daily; Extended-release (Qudexy XR or Trokendi XR) 25 mg once daily for 1 wk, then ↑ to 50 mg once daily for 1 wk, then ↑ by 2550 mg/day at weekly intervals over a 57-wk period to target dose of 250400 mg once daily.
- PO (Children 2<10 yr [6<10 yr for Trokendi XR] and 3238 kg): Immediate-release 25 mg once daily in the evening initially, gradually ↑ at weekly intervals to 125 mg twice daily over a 57-wk period; if needed may continue to titrate dose on a weekly basis up to 175 mg twice daily; Extended-release (Qudexy XR or Trokendi XR) 25 mg once daily for 1 wk, then ↑ to 50 mg once daily for 1 wk, then ↑ by 2550 mg/day at weekly intervals over a 57-wk period to target dose of 250350 mg once daily.
- PO (Children 2<10 yr [6<10 yr for Trokendi XR] and 2331 kg): Immediate-release 25 mg once daily in the evening initially, gradually ↑ at weekly intervals to 100 mg twice daily over a 57-wk period; if needed may continue to titrate dose on a weekly basis up to 175 mg twice daily; Extended-release (Qudexy XR or Trokendi XR) 25 mg once daily for 1 wk, then ↑ to 50 mg once daily for 1 wk, then ↑ by 2550 mg/day at weekly intervals over a 57-wk period to target dose of 200350 mg once daily.
- PO (Children 2<10 yr [6<10 yr for Trokendi XR] and 1222 kg): Immediate-release 25 mg once daily in the evening initially, gradually ↑ at weekly intervals to 100 mg twice daily over a 57-wk period; if needed may continue to titrate dose on a weekly basis up to 150 mg twice daily; Extended-release (Qudexy XR or Trokendi XR) 25 mg once daily for 1 wk, then ↑ to 50 mg once daily for 1 wk, then ↑ by 2550 mg/day at weekly intervals over a 57-wk period to target dose of 200300 mg once daily.
- PO (Children 2<10 yr [6<10 yr for Trokendi XR] and
11 kg): Immediate-release 25 mg once daily in the evening initially, gradually ↑ at weekly intervals to 75 mg twice daily over a 57-wk period; if needed may continue to titrate dose on a weekly basis up to 125 mg twice daily; Extended-release (Qudexy XR or Trokendi XR) 25 mg once daily for 1 wk, then ↑ to 50 mg once daily for 1 wk, then ↑ by 2550 mg/day at weekly intervals over a 57-wk period to target dose of 150250 mg once daily.
Renal Impairment
- PO (Adults): CCr <70 mL/min ↓dose by 50%.
Epilepsy (adjunctive therapy)
- PO (Adults and Children
17 yr): Immediate-release 2550 mg/day initially, ↑ by 2550 mg/day at weekly intervals up to 200400 mg/day in 2 divided doses (200400 mg/day in 2 divided doses for partial seizures or Lennox-Gastaut syndrome and 400 mg/day in 2 divided doses for primary generalized tonic-clonic seizures); Extended-release (Qudexy XR or Trokendi XR) 2550 mg once daily initially, ↑ by 2550 mg/day at weekly intervals up to 200400 mg once daily (for partial seizures or Lennox-Gastaut syndrome) and 400 mg once daily (for primary generalized tonic-clonic seizures). - PO (Children 216 yr): Immediaterelease and extendedrelease (Qudexy XR) 25 mg once daily at night initially for first wk, ↑ at 12 wk intervals by 13 mg/kg/day up to 59 mg/kg/day in 2 divided doses.
- PO (Children 616 yr): Extendedrelease (Trokendi XR) 25 mg once daily at night initially for first wk, ↑ at 12 wk intervals by 13 mg/kg/day up to 59 mg/kg/day given once daily at night.
Renal Impairment
- PO (Adults): CCr <70 mL/min ↓dose by 50%.
Migraine Prevention
- PO (Adults and Children
12 yr): Immediate-release 25 mg at night initially, ↑ by 25 mg/day at weekly intervals up to target dose of 100 mg/day in 2 divided doses; Extended-release (Qudexy XR) 25 mg once daily initially, ↑ by 25 mg/day at weekly intervals up to target dose of 100 mg once daily.
Renal Impairment
- PO (Adults): CCr <70 mL/min ↓dose by 50%.
Qudexy XR, Topamax, Topamax Sprinkle, Trokendi XR
Therapeutic Classification: anticonvulsants