- Anticonvulsant
- Seizure Disorder
- Adjunctive management of Partial Seizures
- Add to primary antiepileptic regimens
- Other potential uses currently being researched
- Myoclonic Seizures
- Infantile Spasm
- Atypical Absence Seizure
- Generalized Tonic Clonic Seizures
- Sulfonamide Allergy
- Pregnancy (Teratogenic in animals)
- Anticonvulsant
- Sulfonamide derivative
- Blocks CNS Sodium and Calcium channels and stabilizes Neuron membranes, preventing hypersynchronization
- Also binds GABA Receptor ionophore complex, but does not appear to potentiate GABA activity at Synapse
- Facilitates the Neurotransmitters Dopamine and Serotonin
- Adults (and age >16 years)
- Initial: 100 mg orally daily for at least 2 weeks
- Increase: 100 mg every two weeks as needed
- Target: 400 mg/day divided once to twice daily
- Maximum: 600 mg/day (but doses above 400 mg/day do not appear to offer benefit)
- Caution: Increase more slowly in Renal Insufficiency and hepatic dysfunction
- Weak carbonic anhydrase inhibitor
-
Sulfonamide that blocks Sodium and Calcium channels
- Increases Dopaminergic transmission
- Increases serotonergic transmission
- Metabolized by CYP3A4
- Drug levels affected by Phenytoin, Carbamazepine, Phenobarbital, Valproic Acid
- Half-Life: 60 hours
- Increased Zonisamide clearance with CYP3A4 inducers
- Concurrent carbonic anhydrase inhibitor (Topamax)
- Increased Nephrolithiasis risk
- Common
- Dizziness
- Ataxia
- Somnolence
- Nausea
- Anorexia
- Abdominal Pain
- Insomnia
- Impaired cognition
- Confusion
- Decreased concentration
- Speech problems
- Serious
- Psychosis
- Stevens Johnson Syndrome
- Toxic Epidermal Necrolysis
- Fulminant hepatic necrosis
- Narrow Angle Glaucoma (IOP may increase during first month of use)
- Childhood Adverse Effects
- Oligohydrosis
- Hyperthermia (and Heat Stroke)
- Other
- Nephrolithiasis (associated with Metabolic Acidosis)