Xanax is the brand name for alprazolam, a prescription medication that belongs to the benzodiazepine class. It is commonly prescribed for the short-term treatment of anxiety disorders and panic disorder. Xanax 2 mg bar is a higher-strength tablet that should only be taken under the guidance of a licensed healthcare professional. Because of its potency, it is not appropriate for everyone and should never be started, stopped, or have its dose changed without medical advice.