Old and new mechanisms of antiepileptic drug actions.

At the present time, between 30% and 50% of individuals with epilepsy continue to have seizures and among those who are considered "controlled", a good many unpleasant side effects are endured. It is clear that we need more and better antiepileptic drugs. The virtual explosion in knowledge about the cellular and molecular mechanisms underlying both normal and pathological reactions of the brain provides encouragement that we are on the right path towards developing new, effective and safe agents. Whether we continue to use "model-based" screening or "mechanism-based screening", or both, we must not go another 14 years without the introduction of a new antiepileptic drug. The problem is too large, our patients are too impatient and our responsibilities are clear.