An Overview of the Pharmacodynamic Properties and Therapeutic Potential of Combined α- and β-Adrenoceptor Antagonists:

Haemodynamically, the combination of α1- and β-adrenoceptor antagonists is a logical one. α1-Adrenoceptor blockade causes vasodilatation and hence counteracts elevated peripheral vascular resistance, the most consistent haemodynamic derangement in established essential hypertension. β-Blockers, which lower elevated blood pressure by a different (not yet clearly understood) mechanism, suppress the reflex tachycardia triggered by vasodilatation. Combined α/β-adrenoceptor blockade can be obtained by the simultaneous administration of both types of adrenoceptor antagonists, but also by giving drugs that possess α- and β-adrenoceptor antagonistic activity in the same molecule.