Alprazolam Xanax 2 mg is a benzodiazepine. It is thought that alprazolam works by enhancing the activity of certain neurotransmitters in the brain. Xanax is a prescription medicine used to treat the symptoms of anxiety, panic disorder, and anxiety associated with depression. Xanax may be used alone or with other medications. Xanax is used to treat anxiety disorders and anxiety caused by depression.