Purpose: This report provides detailed review of safety information on levetiracetam (LEV) (Keppra), a new antiepileptic drug.
Methods: The integrated summary of safety report submitted for regulatory review was examined to collate information about abnormal laboratory tests values and adverse event reports collected during the overall LEV development program. Analyses included 3347 patients exposed to LEV in clinical trials for epilepsy, cognition, and anxiety disorders.
Results: Safety data from all studies depict a similar pattern of adverse effects, predominantly somnolence, asthenia, and dizziness that occurred most frequently during the first month of LEV treatment. Changes in laboratory test values from placebo-controlled trials that were statistically significant remained in the normal range (red blood cells, hematocrit, hemoglobin, white blood cells, and neutrophils). Reports of the coding term 'infection' (common cold, upper respiratory infection) were not preceded by low neutrophil counts that might suggest impaired immunological status. Selection of adverse event coding terms probably contributed to the high rate of adverse effects termed 'infection.' Higher incidences of adverse effects, particularly behavioral effects, were found among epilepsy patients than in elderly patients with cognitive disorders or patients with anxiety disorders given lower doses.
Conclusions: This review of patients evaluated during the clinical development program suggests that LEV was well tolerated and safe for patients with seizure, cognitive and anxiety disorders. Overall incidence of adverse effects in the LEV groups was little higher than reports from the placebo groups. Of course, this data was derived from clinical trials that are of relatively short duration, and provide data on only several thousand patients. Therefore, long-term side effects, and/or rare side effects cannot be ruled out on the basis of this analysis.