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 nifedipine or placebo on alternate mornings in a double-blind fashion. Patients were trained in a protocol that precipitated angina after 3-6 min 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 h. Mean exercise duration was greater 1 h after nifedipine than after placebo by 123 s (372 .+-. 21 vs. 249 .+-. 16 s, P < 0.001). By the 5th h, the increase in exercise time was reduced to 93 s (P < 0.001), and a significant, although further diminished, difference of 57 s was still present at 8 h (P < 0.01). Nifedipine lowered resting systolic blood pressure by 20 mm Hg (P < 0.001) without appreciably changing heart rate. Nifedipine apparently is a very effective and reasonably long-acting antianginal supplement to propranolol.