Drug treatment of epilepsy in the 1990s. Achievements and new developments.

There have been significant advances in the medical treatment of epilepsy in recent years. Improved formulations of several classical antiepileptic drugs (AEDs) have appeared, resulting in improved efficacy and decreased toxicity. A marked increase in the number of comparative investigations of AEDs has also made treatment choice somewhat simpler. Rational methods applied in the search for new AEDs have resulted in the introduction of several new AEDs. So far, evidence seems to indicate that progress has been made with regard to developing compounds not necessarily with superior efficacy but with simpler pharmacokinetics, avoiding enzyme induction as well as decreasing the number of interactions, and improving adverse effect profiles, in comparison to the previous generation of AEDs. A novel approach to the clinical testing of AEDs has made it possible to demonstrate unequivocal efficacy, as well as efficacy as monotherapy, very early in the development of novel compounds. Results of studies from developing countries seem to raise doubt with regard to the value of the old dogmatic principle that early treatment is important in terms of the long term prognosis for seizure control. Traditional ideas on the value of monotherapy have also been questioned on the basis of a novel concept of so-called 'rational polytherapy' which, however, still await scientific validation. On the basis of excellent epidemiological and large controlled clinical studies, our ideas of the necessary duration of AED treatment have become much more optimistic than before.