Klonopin is a brand name for the medicationClonazepam which belongs to the class of drugs called benzodiazepines.Klonopin is commonly prescribed to treat anxiety disorders, insomnia, seizures, and other medical conditions. It works by slowing down the activity of the brain and nervous system, producing a calming effect on the body. Klonopin is a prescription drug and should only be used under the guidance of a healthcare provider.