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). 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).   Lorazepam, sold under the brand name Ativan among others, is a benzodiazepine medication. It is used to treat anxiety disorders, trouble sleeping, active seizures including status epilepticus, alcohol withdrawal, and chemotherapy-induced nausea and vomiting. Wikipedia Formula: C15H10Cl2N2O2 Molar mass: 321.2 g/mol Boiling point: 533.8 °C CAS ID: 846-49-1 ChemSpider ID: 3821 ChemSpider ID: 3821 People also search for: Alprazolam, Diazepam, Clonazepam.