Lorazepam is a drug used in the treatment of anxiety-based disorders. It may also be used in the treatment of certain types of epilepsy. It belongs to a group of drugs known as benzodiazepines, which work by enhancing the effects of GABA - the principal inhibitory neurotransmitter in the brain.Lorazepam belongs to the drug class of benzodiazepines. This drug class acts on the nerve and brain, which is the central nervous system, to produce a calming effect. It is used to treat patients with anxiety disorders. Lorazepam may also be used to for trouble sleeping which is insomnia, prevent vomiting and nausea due to chemotherapy, and reduce the symptoms of alcohol withdrawal. This medication works by enhancing the effect of the certain natural chemical in the body known as GABA. If you have a history of personality disorder, drug abuse, alcoholism, or you have used Lorazepam regularly for a long period or in high doses, it may cause withdrawal reactions.