• schizophrenia
• antipsychotic drugs
• risperidone
• antisaccade error rate
• cognitive function tests

• LEV, levetiracetam
• PTZ, pentylenetetrazol
• GABA, γ-aminobutyric acid
• GAD, glutamic acid decarboxylase
• SUDEP, sudden and unexplained death in epilepsy

Recently a new antiepileptic drug, levetiracetam (LEV), was approved for the add on treatment of partial epilepsy, both in the United States and in Europe. This is of potential importance, because this drug is from a class not previously used in epilepsy, although piracetam, a compound with a structure similar to that of levetiracetam, is useful in myoclonus. Both drugs are pyrrolidone derivatives, a class of drugs of interest for both psychotropic and nootropic applications and potentially as neuroprotectants. Levetiracetam (available under the registered trademark of UCB S.A., Keppra^R) is the S-enantiomer of α-ethyl-2-oxo-1-pyrrolidine acetamide (fig 1). Homologues sharing the S configuration include a range of other compounds, some of which also have antiepileptic action.¹ The range and extent of the compounds' activity in experimental models of epilepsy and other conditions varies considerably with minor changes to chemical structure, but the full extent of the range of properties of these drugs in humans has not been explored. This article reviews the experimental and clinical data relating to the antiepileptic action of levetiracetam.