Ativan, which is the brand name for Lorazepam, is a medication in the benzodiazepine class of drugs. It is commonly used to treat conditions such as anxiety, insomnia, and seizure disorders, as well as to provide sedation before surgeries or medical procedures. As with other benzodiazepines, Ativan works by acting on the central nervous system (CNS), producing a calming effect on the brain and body.