[Drug treatment of myocardial ischemia]

Nitrates are the basic medication of patients suffering from coronary heart disease. Frequently they are combined with calcium-antagonists or beta-receptor-blocking agents. The dose of 20 mg non-retarded dinitrates or mononitrates three times a day have the same effect as retarded nitrates once a day but of a higher dose (60-120 mg). The meaning of this drug has increased because of new results on the mechanism of action: nitric oxide is able to substitute the missing EDRF in the injured intima and leads to dilatation of the stenosis. This mechanism is the basis for the antianginal effect. Already minimal doses (0.025 mg nitroglycerine i.v. 1.25 mg isosorbide dinitrate oral) are effective independent of the dilatation of peripheral venous and arterial vessels. The antiaggregatory effect decrease thrombus formation in patients with unstable angina and the risk of infarction and produce a kind of rinsing effect in the stenosis. The size of infarction becomes smaller, the expansion of the ventricle is less and the prognosis improved. Concerning the calcium-antagonists dihydropiridine-preparations, verapamil and diltiazem have to be separated. Arterial vasodilatation of nifedipine may increase heart rate during exercise and rarely coronary steel phaenonemen. In contrast verapamil (3 x 120 mg) and gallopamil (3 x 50 mg) have strong antianginal effects and reduce the ischemic reaction during exercise about 50%. Heart rate is reduced during physical exercise, similar to the beta-receptor-blocking agents. AV-blocks are rare. Obstipation is more frequent with verapamil than with gallopamil. Verapamil decreases the infarct size and improves the prognosis after infarction in patients without left ventricular failure.(ABSTRACT TRUNCATED AT 250 WORDS)