Use of a new antiepileptic drug or an old one as first drug for treatment of absence epilepsy.

Treatment of absence epilepsy requires understanding the efficacy and side effects of several drugs, one of which first became available more than 50 years ago. Methods for drug development and procedures for evaluating their safety and efficacy over that time have changed dramatically. Observational studies of the efficacy of ethosuximide, a drug developed in the 1950s, reported complete seizure control in 40-60% of patients. Valproic acid, a drug with a broad spectrum of effect, showed robust efficacy as well for control of absence seizures. Because side effects limit use in some patients, newer drugs were evaluated in patients with absence seizures. Of drugs becoming available in the last 15 years, lamotrigine has some effect in absence seizures. Although older and newer drugs presently are used without the rigorous underpinnings of the highest quality of evidence, our analysis found that ethosuximide, valproate, and lamotrigine are effective in the treatment of absence seizures, with ethosuximide quite possibly being the first drug of choice.