A risk-benefit assessment of carvedilol in the treatment of cardiovascular disorders.

Carvedilol is a nonselective beta-adrenoceptor blocking vasodilator drug that may be a promising new agent in the management of cardiovascular disease. The rationale for the development of agents of this type is that the alpha-blocking component may overcome the direct vasoconstrictor consequence of beta 2-blockade, whilst the beta-blocker component may inhibit the reflex tachycardia that occurs following alpha-blockade. In clinical trials published to date, carvedilol has been demonstrated to be effective as an antihypertensive agent as monotherapy and also as additional therapy in those patients whose blood pressure cannot be controlled on other standard agents. It is also effective in the management of angina. Carvedilol has beneficial haemodynamic effects in patients with congestive heart failure. beta-Blocker vasodilator drugs of this type may be particularly useful in this condition as the vasodilator component of the drug may overcome the initial negative inotropy of the beta-blocker. In addition, carvedilol possess potentially useful pharmacological actions. In particular, the drug has antimitogenic and free radical scavenging effects that may make it a useful therapy in the long term management of atherosclerotic vascular disease. Its metabolic profile is also favourable, presumably on the basis of its alpha-blocking properties. Thus, beta 2-mediated adverse effects on peripheral vascular tone, glycaemic control and lipid status appear to be offset by the alpha-blocking property of the drug. Carvedilol thus far appears to be well tolerated, with postural dizziness the major adverse effect, especially in the elderly. As with nonselective beta-blockers, carvedilol is contraindicated in patients with asthma.