New antiepileptic drugs: A critical review

All antiepileptic drugs (AED) introduced after 1990 are called 'New' as there was a long time gap between valproate and the first new drug (vigabatrin). Most of them are licensed for focal onset seizures in adults, some in children. Only few drugs have special indications in childhood epilepsy syndromes.

As most of these drugs are in use for many years now we have sufficient safety data. Most of these drugs are safe (exeptions: felbamate, vigabatrin) and have less side effects than equally effective older drugs. But in terms of efficacy they are not generally better than their old counterparts.

The chance to become seizure free has increased only by a few percents, the amount of seizure free patients in clinical (add on) studies is below 10% over 3–6 months and drops with longer follow up times.

Most of the new drugs have similar molecular targets as the older drugs (sodium channels, some types of Ca channels, GABA and glutamate receptors) and therefore do not have groundbreaking new mechanisms of action. Minor differences in the channel/receptor population reached lead to individual effect/side effect profiles. We have to learn that a pharmacoresistance is a more general problem that is not addressed by the anticonvulsants.

But there are benefits of new AED in terms of side effects and interactions. The chance of finding an individually good tolerable therapy increases with the number of available treatment options. Good examples can especially found in juvenile generalized epilepsies, maybe in very young children, too.