Alprazolam, commonly marketed under the brand name Xanax, is a medication classified as a benzodiazepine. Like other benzodiazepines, alprazolam works by enhancing the effects of a neurotransmitter in the brain called gamma-aminobutyric acid (GABA). This neurotransmitter helps to regulate the excitability of nerve cells in the brain, leading to a calming effect on the central nervous system.