Information about Zonisamide
Zonisamide is a new generation anticonvulsant that is typically used in combination with other antiepileptic medications for partial onset seizures.
Liver safety of Zonisamide
Zonisamide has not been associated with elevations in serum aminotransferase levels and clinically apparent drug induced liver disease has been reported with its use but is very rare.
Mechanism of action of Zonisamide
Zonisamide (zoe nis' a mide) is synthetic sulfonamide derivative related somewhat in structure to acetazolamide, but not to other anticonvulsant medications. Zonisamide appears to block the spread of seizure discharges by affecting repetitive firing of voltage-sensitive sodium and calcium channels and stabilizing neuronal membranes.
FDA approval information for Zonisamide
Zonisamide was approved for use in epilepsy in Japan in 1989 and in the United States in 2000.
Clinical use of Zonisamide
Current indications include adjunctive therapy for partial seizures in adults. Zonisamide is used off-label for therapy of migraine headaches, mood disturbances and recently for weight loss.
Dosage and administration for Zonisamide
Zonisamide is available as capsules of 25, 50 and 100 mg generically and under the brand name of Zonegran. The recommended initial dose in adults with epilepsy is 100 mg in one or two doses daily, with dose escalation based upon tolerance and effect to a maximum of 200 mg twice daily.
Side effects of Zonisamide
Common side effects include drowsiness, dizziness, headache, nausea, poor appetite and weight loss. Rare, but serious side effects include Stevens Johnson syndrome, toxic epidermal necrolysis, aplastic anemia and agranulocytosis.