Clonazepam is used alone or in combination with other medications to control certain types of seizures. It is also used to relieve panic attacks (sudden, unexpected attacks of extreme fear and worry about these attacks).  Clonazepam, sold under the brand name Klonopin among others, is a medication used to prevent and treat seizures, panic disorder, and the movement disorder known as akathisia. It is a tranquilizer of the benzodiazepine class