Clinical studies of topiramate.

Topiramate had well-documented efficacy as an adjunctive agent for partial-onset seizures in 5 double-blind, parallel trials, reducing seizure frequency by 35-47% at 400 mg/day, the optimal dose for most patients. It can also be used as monotherapy for partial-onset seizures. A broad spectrum of action is suggested by studies showing efficacy against a variety of generalized-onset seizure types, including primary generalized tonic-clonic seizures and the component seizures of Lennox-Gastaut syndrome. The major adverse effects of topiramate are of CNS origin. Psychomotor slowing is most common, but disappears in most patients with time or dosage adjustments; 11-28% of patients discontinue the drug because of side effects. No serious skin, liver or blood toxicity has been identified. Efficacy and adverse effect profiles are similar for children and adults. Introduction at rates not exceeding 25-50 mg increases per week will minimize adverse effects and be satisfactory for most adults.