H-1-antihistamines

The therapeutic index of an H-1-antihistamine depends on several biochemica l aspects: pharmacokinetics, metabolism, tissue distribution, lack of inter ference with active transport systems and existence of anti-allergic activi ties. Although the ideal H-1-antagonist does not yet exist, new approaches will probably allow the synthesis of more potent and more specific drugs in the near future. In this paper, we are going to briefly review the present knowledge about the available H-1-antihistamines.