Translating monotherapy trials into clinical practice: a look into the abyss.

To be approved for monotherapy by regulatory authorities, new antiepileptic drugs (AEDs) must first be tested in well-controlled studies in refractory patients (conversion to monotherapy trials) or in patients with newly diagnosed epilepsy. However, the applicability of the information obtained in these trials to day-to-day clinical practice is limited. Clinical trials in newly diagnosed patients, particularly those allowing dose flexibility, offer more useful information, but a close scrutiny of methodological details is required to avoid misinterpretation of the findings. In many instances, the neurologist has a drug with a label, but lacks critical information on optimal titration rates, optimal target and maintenance dosages, response rates in populations with different epilepsy syndromes, different age ranges and comorbidities, and long-term safety data. Such information becomes available only through general clinical experience, well-designed phase IV studies, and postmarketing surveillance.