Xanax belongs to the benzodiazepine class of anti-anxiety medications. Diazepam (Valium), clonazepam (Klonopin), lorazepam (Ativan), flurazepam (Dalmane), and other benzodiazepines belong to this family. Buy Xanax Online works by reducing excessive nervousness in the brain and was approved by the Food and Drug Administration (FDA) in October 1981. The brain and central nervous system are calmed by benzodiazepines (CNS).