Abstracts

RATIONALE: Levetiracetam (LEV) is a new antiepileptic drug (AED) recently approved in the US and Switzerland for add-on treatment of partial seizures in adults. LEV s efficacy as an add-on treatment for partial onset seizures has been previously reported. One commonly accepted method to compare efficacy is by calculating The Number Needed To Treat (NNTT). NNTT is defined as the number of patients that must be exposed to a drug to get either one responder (?50% seizure reduction) or one seizure free patient. METHODS:_ We used the method described by Cook and Sackett (1995) with SAS software and analyzed data pooled from the 3 well-controlled studies (904 patients: 592 on LEV, 312 on placebo) during the evaluation period as well as during the treatment period (titration plus evaluation). RESULTS:_ During the evaluation period the LEV patient NNTT to get one responder was 4.82 (3.85-6.45) and to get one seizure free patient was 20.27 (14.32-34.67). During the treatment period the LEV patient NNTT to get one responder was 3.92 (3.28-4.88) and to get one seizure free patient was 24.56 (17.13-43.47). CONCLUSIONS: These calculations offer another method of demonstrating the efficacy profile for LEV. Together with its pharmacokinetic and safety profiles, the NNTT values suggest that LEV is a promising new AED.