Zonisamide
Mechanism :
by changing the voltage-dependent sodium channel's fast inactivation threshold, lowers sustained high-frequency repeated firing of action potentials.
Indication :
- Adjunctive therapy in the management of partial seizures in patients more than 16 years.
Contraindications :
Zonisamide / Sulfonamide hypersensitivity
Pregnancy category: C
caution in age less than 16 years
caution if renal impairment
caution if hepatic impairment
caution if nephrolithiasis
caution if metabolic acidosis
Dosing :
<16 years:
Not recommended
>16 years:
Oral 100-600 mg/day divided daily or twice daily.
Start: 100 mg PO daily, may increase by 100 mg/day every 2 weeks.
Maximum: 600 mg/day, though, doses >400 mg/day are seldom more effective. Taper dose gradually to D/C
Adverse Effect :
anorexia, Somnolence, headache, dizziness, nausea, agitation
Interaction :
Antipsychotics
Opioids
Atropine
Chlorpheniramine
Acetazolamide
Dicyclomine
SSRIs
Glycopyrrolate
Metformin
Hepatic Dose :
hepatic impairment: caution advised, titrate slowly