Clonazepam is used alone or in combination with other medications to control certain types of seizures and spasticity. It is also used to relieve panic attacks (sudden, unexpected attacks of extreme fear and worry about these attacks). Clonazepam is in a class of medications called benzodiazepines. It works by decreasing abnormal electrical activity in the brain.
Summary from MedlinePlus.gov, click for more information.