Uses. This medication is used to treat anxiety. Lorazepam belongs to a class of drugs known as benzodiazepines which act on the brain and nerves (central nervous system) to produce a calming effect.This drug works by enhancing the effects of a certain natural chemical in the body (GABA).his medication is used to treat anxiety. Lorazepam belongs to a class of drugs known as benzodiazepines which act on the brain and nerves (central nervous system) to produce a calming effect.