Efficacy and safety of levetiracetam in Japanese epilepsy patients: A retrospective cohort study

What is known and objective Levetiracetam is an antiepileptic drug with good tolerability that is used for focal and generalized epilepsy as well as acute treatment of status epilepticus; it is also a first-line antiepileptic drug for patients with concomitant medical conditions. The effect of blood levetiracetam concentration on its efficacy and safety in Japanese patients with epilepsy is unknown. Methods This retrospective cohort study compared the efficacy and safety of levetiracetam alone and in combination with other antiepileptic drugs in 255 outpatients with epilepsy treated with levetiracetam. Electronic medical records were accessed to analyse clinical parameters including blood concentrations of levetiracetam and concomitant antiepileptic drugs, clinical laboratory values and adverse reactions. Results and discussion Combination of levetiracetam with antiepileptic drugs, even those that alter cytochrome P450 activity, did not affect blood levetiracetam concentrations. Similarly, levetiracetam use did not significantly affect blood concentrations of concomitantly used antiepileptic drugs. Although blood levetiracetam concentration was significantly increased in older patients and those with renal dysfunction, the rates of adverse reactions were not increased. What is new and conclusion Levetiracetam may be used effectively and safely without dose adjustment using blood concentration monitoring even when administered in combination with other antiepileptics for Japanese patients with epilepsy.