text: Levetiracetam, sold under the brand name Keppra among others, is a medication used to treat epilepsy. It is used for partial-onset, myoclonic, or tonic–clonic seizures and is taken either by mouth as an immediate or extended release formulation or by injection into a vein.
  Common side effects of levetiracetam include sleepiness, dizziness, feeling tired, and aggression. Severe side effects may include psychosis, suicide, and allergic reactions such as Stevens–Johnson syndrome or anaphylaxis.  Levetiracetam is the S-enantiomer of etiracetam. Its mechanism of action is not yet clear.
  Levetiracetam was approved for medical use in the United States in 1999 and is available as a generic medication. In 2021, it was the 101st most commonly prescribed medication in the United States, with more than 6million prescriptions. It is on the World Health Organization's List of Essential Medicines.