The additive antianginal action of oral nifedipine in patients receiving propranolol. Magnitude and duration of effect

Abstract

Ten men with stable angina not completely relieved by full doses of propranolol (mean 218 mg/day) were administered an oral dose of 10 mg of nifedipine or placebo on alternate mornings in a double-blind fashion. Patients had been trained in a protocol that precipitated angina after 3-6 minutes of bicycle exercise. On test days, with propranolol continued, bicycle exercise to angina or fatigue was performed before nifedipine or placebo administration, and hourly thereafter for 8 hours. Mean exercise duration was greater 1 hour after nifedipine than after placebo by 123 seconds (372 ± 21 vs 249 ± 16 seconds, p < 0.001). By the 5th hour, the increase in exercise time was reduced to 93 seconds (p < 0.001), and a significant, though further diminished, difference of 57 seconds was still present at 8 hours (p < 0.01). Nifedipine lowered resting systolic blood pressure by 20 mm Hg (p < 0.001) without appreciably changing heart rate. We conclude that nifedipine is a very effective and reasonably long-acting antianginal supplement to propranolol.