The prolonged effect of pentaerythritol tetranitrate on exercise capacity in stable effort angina pectoris.

We studied the effect of a single oral dose of 40 mg of pentaerythritol tetranitrate (PETN) on the exercise capacity of ten patients with angina pectoris. The study design was a randomized double-blind crossover comparing the effects of 40 mg of oral PETN with placebo on exercise tolerance. Patients were exercised to moderate angina pectoris before and 2 1/2 and 4 1/2 hours after receiving the placebo or PETN at seven-day intervals during the double-blind crossover period. Exercise tolerance time was measured using a multistage, progressive treadmill test. Exercise times were greater 2 1/2 hours and 4 1/2 hours following PETN compared with placebo (P less than 0.05). Heart rate, systolic and diastolic blood pressure, and double product at rest (supine and standing) and at point of angina pectoris did not change significantly.