Comparative Pharmacology
Head-to-head clinical analysis: DILANTIN versus ZONISAMIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DILANTIN versus ZONISAMIDE.
DILANTIN vs ZONISAMIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Phenytoin stabilizes neuronal membranes and decreases seizure activity by increasing efflux or decreasing influx of sodium ions across cell membranes in the motor cortex during generation of nerve impulses. It acts by blocking voltage-dependent sodium channels, thereby inhibiting the spread of seizure activity.
Anticonvulsant; blocks voltage-gated sodium channels and T-type calcium channels, reducing neuronal excitability and seizure propagation. Also weakly inhibits carbonic anhydrase.
300–400 mg/day orally in 2–3 divided doses; IV loading dose 15–20 mg/kg at max 50 mg/min, then 300 mg/day IV divided 2–3 times daily.
Oral, initial 100 mg daily, may increase by 100 mg every 2 weeks; maintenance 200-400 mg daily in 1-2 divided doses; maximum 600 mg daily.
None Documented
None Documented
Clinical Note
moderateZonisamide + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Zonisamide."
Clinical Note
moderateZonisamide + Erythromycin
"The metabolism of Erythromycin can be decreased when combined with Zonisamide."
Clinical Note
moderateZonisamide + Cyclosporine
"The metabolism of Cyclosporine can be decreased when combined with Zonisamide."
Clinical Note
moderateZonisamide + Fluconazole
Average 22 hours (range 7-42 hours) in adults. Dose-dependent; increases with higher concentrations due to saturable metabolism. In neonates: 10-15 hours. In chronic use, half-life may increase.
Terminal half-life approximately 60-70 hours (range 50-80 hours) in adults; at steady state, half-life may be slightly longer. Clinical context: requires 2-3 weeks to achieve steady state.
Primarily hepatic metabolism to inactive metabolites (p-hydroxyphenyltoin and glucuronide conjugate). Less than 5% excreted unchanged in urine. Fecal excretion minimal (<2%).
Renal: approximately 30% unchanged; remainder as glucuronide conjugate and reduced metabolite. Biliary/fecal: minimal (<5%).
Category C
Category C
Anticonvulsant
Anticonvulsant
"The metabolism of Fluconazole can be decreased when combined with Zonisamide."