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. Lorazepam is a benzodiazepine (ben-zoe-dye-AZE-eh-peen). Lorazepam affects chemicals in the brain that may be unbalanced in people with anxiety. Lorazepam is used to treat anxiety disorders. Lorazepam may also be used for purposes not listed in this medication guide. Lorazepam (trade name Ativan) is a depressant substance of the benzodiazepine class. Lorazepam is used for the short-term treatment of anxiety, insomnia, acute seizures, and the sedation of hospitalized patients.. Users should note that that as with benzodiazepines, the sudden discontinuation of thienodiazepines can be dangerous or even life-threatening for long-term or heavy users.