Adverse response to nifedipine in unstable angina pectoris.

A patient had accelerated attacks of chest pain associated with transient ST elevation or depression in the anterior leads. Coronary angiogram revealed severe multi-vessel disease. Anginal attacks with conspicuous ST depression were induced repeatedly by both oral and sublingual administration of nifedipine. Among various vasodilator drugs tested on this patient, dipyridamole and hydralazine induced anginal attacks. These observations suggest that anginal attacks induced by administration of nifedipine may be related to the augmentation of myocardial oxygen consumption due to increases in cardiac output and heart rate, the coronary steal phenomenon, or an increase in venous return accompanied by the subendocardial underperfusion.