Alpha- and beta-blocking agents: pharmacology and properties
Donald G. Vidt, MD
Alan Bakst, PharmD
B.N.C. PrichardAddress reprint requests to B.N.C.P., Head, Department of Clinical Pharmacology, University College London, 5 University Street (The Rayne Institute), London WCIE 6JJ, England.
Adrenergic receptors have been separated into alpha and beta groups, which have then been further subdivided. Agents have been developed that block each type of receptor with varying degrees of specificity between the sub-types, leading to differences in pharmacodynamic profile. A more recent innovation has been the development of multiple action beta-blocking drugs, ie, those not only blocking the beta receptors but also posessing a peripheral vasodilator effect that may be due to alpha blockade, beta-2 stimulation, or a vasodilator action independent of either alpha or beta receptors.