Alprazolam binds with high affinity to the GABA benzodiazepine receptor complex. Considerable evidence suggests that the central pharmacologic or therapeutic actions of alprazolam are mediated via interaction with this receptor complex.
Alprazolam, a benzodiazepine, bind nonspecifically to benzodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABAA) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of the inhibitory neurotransmitter GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.