The impact of new antiepileptic drugs on the prognosis of epilepsy: seizure freedom should be the ultimate goal.

Abstract

King Henry II turned to his entourage and said \``Will none of these cowards rid me of this upstart priest,'' and immediately four knights travelled to England and slaughtered Thomas a Becket. This was a successful execution of a simple command. Yet if an analogous request is made by those with epilepsy, \``Will none of these AEDs rid me of this condition,'' it has been generally accepted that rid implies rid at least 50% of the time (the equivalent of organizing a sabbatical for Thomas a Becket). Although this analogy may seem frivolous, it brings into question the idea of success when new antiepileptic drugs (AEDs) are assessed in clinical trials as add-on therapy. There are two distinct populations that may be helped by new AEDs: newly diagnosed patients and patients with refractory disease. Initial assessment of new AEDs in newly diagnosed patients is possibly unethical as it involves denying patients known effective therapy-80% may expect to become seizure-free on monotherapy with established AEDs. [1] Assessment in this group is therefore reserved for new AEDs that have been established as effective therapy in patients with refractory disease. New AEDs, however, cannot be compared against placebo in newly diagnosed patients as that would deny those patients effective therapy. New AEDs thus have to be compared against established drugs, and if the null hypothesis that the two drugs are equally efficacious is not rejected, the conclusion could be that the drugs are equally ineffective. [2] The comparison may be further confounded by suggestions that there is a spontaneous remission rate of at least 30% for this group regardless of AED therapy. [3] In addition, it is difficult to establish the effect on prognosis from these trials (i.e., will a greater number of patients become seizure-free if the new AED is used as …