Preclinical and clinical pharmacology of carvedilol

Carvedilol is a novel multiple-action cardiovascular drug that has recently been introduced to the market for the treatment of mild to moderate hypertension. Clinical studies have demonstrated that once daily therapy with carvedilol is efficacious and has a favourable side-effect profile. Clinical studies are in progress to establish the utility of carvedilol in angina and congestive heart failure. Carvedilol is a beta-adrenoceptor antagonist and a vasodilator, with the vasodilating activity resulting primarily from alpha 1-adrenoceptor blockade and possibly also from calcium channel blockade. The reduction in BP produced by carvedilol results from the vasodilating activity of the drug because peripheral vascular resistance is significantly reduced. The reduction in BP produced by carvedilol is not associated with reflex tachycardia owing to the beta-adrenoceptor blocking activity of the compound. Throughout its antihypertensive dose range, carvedilol has been a renal-sparing antihypertensive agent in animals and also in humans, inasmuch as renal blood flow, glomerular filtration rate and sodium excretion are all maintained. In preclinical experimental models of acute myocardial infarction, carvedilol has produced marked reductions in infarct size in the pig, rat and dog. The cardioprotection observed with carvedilol is greater than that provided by beta-adrenoceptor antagonists alone, suggesting that the additional activities of carvedilol may provide benefit in the setting of myocardial ischaemia.