Losigamone: A putative antiepileptic drug

Losigamone (LSG) has shown anticonvulsant efficacy and low neurotoxicity in preclinical testing and has been tolerated in Phase I clinical trials. We report an open-label, add-on tolerability study of sb ascending LSG dosage levels from 600 to 2,100 mg daily in patients receiving phenytoin (PHT), carbamazepine (CBZ), or combination PHT/CBZ. Dosage was escalated weekly, with assessment including reports of adverse events (AE), seizure diary, neurologic and physical examination, electrocardiogram (EGG), and laboratory tests. No serious AE were reported, and those most common AE were headache and dizziness. No significant alteration in PHT, CDZ, or CBZ-epoxide(CBZ-E) levels was noted. No clinically significant change in laboratory tests was noted. A median seizure reduction during LSG treatment as compared with baseline of 39% was achieved during the study. All 9 patients continued into an extension study, and 3 have remained seizure-free for as long as 2 years. Some brief increases in seizure frequency were evident at the 1,800- and 2,100-mg daily dosage levels. We conclude that continued evaluation of LSG for the treatment of partial seizures is indicated. (C) 1997 by G. L. Morris III et al.