THE THERAPEUTIC OBJECTIVES IN THE USE OF ANTIANGINAL DRUGS
The major therapeutic objectives in the treatment of angina are aimed at terminating or preventing an acute attack and increasing the patient’s exercise capacity. These objectives can be achieved by reducing overall myocardial oxygen demand or by increasing oxygen sup-ply to ischemic areas. A decrease in myocardial oxygen demand can be attained through use of the organic ni-trates, calcium entry blockers, and β-adrenoceptor block-ing agents. Increases in myocardial oxygen supply are more difficult to achieve, especially when coronary blood vessels are partially or totally obstructed.
However, re-distribution of blood flow to the subendocardium of ischemic areas has been documented in experimental an-imals following nifedipine (Adalat, Procardia), diltiazem (Cardizem),verapamil (Calan), amlodipine (Norvasc), ni-troglycerin (Nitrostat, Tridil, Nitro-Dur), or propranolol (Inderal) administration. Increases in collateral flow to ischemic areas also have been observed in experimental animals and humans after treatment with certain calcium entry blockers and organic nitrates.
When coronary vasospasm occurs, the balance be-tween oxygen supply and demand can be restored by re-lieving the spasm, thereby restoring normal coronary blood flow. Acute vasospasm has been successfully aborted through the use of nitroglycerin. In contrast, cal-cium entry blockers and long-acting nitrates have proved effective in the chronic therapy of coronary vasospasm.