Levetiracetam, marketed under the trade name Keppra among others, is a medication used to treat epilepsy. It is used for partial onset, myoclonic, or tonic-clonic seizures. It is the S-enantiomer of etiracetam. Levetiracetam is available by mouth in two forms: immediate release and extended release. An immediate release tablet has been available as a generic in the United States since November 2008, and in the UK since 2011. The United States patent for the extended release tablet expires September 17, 2028. It was initially patented by UCB Pharma.