Kumulerede sikkerhedsdata fra kliniske afprøvninger med orale Keppra formuleringer udført med voksne patienter med anfald af partiel type viste at 46, 4% af patienterne i Keppragruppen og 42, 2% af patienterne i placebogruppen fik bivirkninger.
Pooled safety data from clinical studies conducted with Keppra oral formulations in adult patients with partial onset seizures showed that 46.4% of the patients in the Keppra group and 42.2% of the patients in the placebo group experienced undesirable effects.