Ativan is a prescription medication that is primarily used to treat anxiety disorders, insomnia, and seizures. The active ingredient in Ativan is lorazepam, which belongs to a class of drugs known as benzodiazepines. Benzodiazepines work by enhancing the effects of a neurotransmitter in the brain called gamma-aminobutyric acid (GABA), which helps to reduce anxiety and promote relaxation.