Levetiracetam: A Different Approach to the Pharmacotherapy of Epilepsy

Abstract

OBJECTIVE: To review the pharmacology, pharmacokinetics, efficacy, and adverse effects of levetiracetam in the treatment of epilepsy. DATA SOURCES: A MEDLINE search restricted to English-language publications was conducted (January 1993–October 2000). Unpublished data provided by the manufacturer and information found in proceedings of professional meetings were also included. DATA EXTRACTION/STUDY SELECTION: Information regarding basic pharmacology was collected from studies in animals. Pharmacokinetic data were collected from human trials. Only randomized, placebo-controlled clinical trials were included to describe the efficacy and safety of levetiracetam. DATA SYNTHESIS: Levetiracetam is a new antiepileptic drug (AED) that appears to work by a unique mechanism. Animal studies have shown that levetiracetam may prevent epileptogenesis. Levetiracetam is rapidly and completely absorbed, minimally bound to plasma proteins, eliminated through the kidneys, and has a half-life of 6–8 hours. Doses must be adjusted for varying degrees of renal function. In clinical trials, levetiracetam significantly decreased seizure frequency compared with placebo when added to existing AED regimens. One clinical trial indicated that levetiracetam may be effective as monotherapy. Few major adverse effects were reported in the clinical trials; however, several patients reported psychological and psychotic reactions. CONCLUSIONS: Levetiracetam is a safe and effective new AED. Its apparent unique mechanism of action makes levetiracetam an important addition to therapy with older medications. Caution should be exercised when administering levetiracetam to individuals who may be prone to psychotic or psychiatric reactions.