Zonisamide: A Review of Its Use in the Management of Adults with Partial Seizures

Oral zonisamide (Zonegran (R)) is a benzisoxazole derivative chemically unrelated to other antiepileptic agents. It is indicated in the EU as monotherapy in the treatment of partial seizures, with or without secondary generalization, in adults with newly diagnosed epilepsy and as adjunctive therapy to other antiepileptic drugs (AEDs) in the treatment of adults with partial seizures, with or without secondary generalization. In a double-blind, multinational study in adults newly diagnosed with partial seizures, shorter-term monotherapy with once-daily zonisamide was noninferior to that with twice-daily carbamazepine controlled release in terms of seizure freedom according to the International League Against Epilepsy guidelines, with seizure freedom benefits maintained during longer-term therapy. In four randomized, double-blind, placebo-controlled studies in adults with refractory partial seizures, shorter-term adjunctive therapy with once-or twice-daily zonisamide reduced the frequency of seizures to a significantly greater extent than placebo, with antiepileptic efficacy sustained following longer-term treatment in this patient population. Zonisamide was generally well tolerated in adults with partial seizures participating in these studies, with the majority of adverse events being mild or moderate in severity. Thus, oral zonisamide as monotherapy or adjunctive therapy to other AEDs provides a useful option in the treatment of patients with partial seizures.