What is a fair comparison in head-to-head trials of antiepileptic drugs?

1report a landmark study comparing lamotrigine and pregabalin in patients with newly diagnosed partial epilepsy. This large double-blind trial is the latest in a series of comparative eff ectiveness studies of antiepileptic drugs, but it is the fi rst to show superiority of one new antiepileptic drug compared with another in this group of patients. Pregabalin was less able to render patients seizure-free than was lamotrigine, and the two drugs had similar tolerability. Both lamotrigine and pregabalin have been proven to be effi cacious for the treatment of epilepsy. Pregabalin is the more recently approved drug. It has previously been studied only in patients with treatment-resistant partial onset seizures, in whom it seemed highly effi cacious: in add-on trials at the highest dose, 50% of patients had a 50% reduction in seizures. 2 Lamotrigine is effi cacious in both partial and generalised epilepsy, in both newly diagnosed and treatment-resistant patients.