Acute effects of nifedipine, diltiazem and their combination in patients with chronic stable angina: a double-blind, randomized, cross-over, placebo-controlled study.

We evaluated the acute therapeutic effects of the oral administration of nifedipine (10 mg) and diltiazem (120 mg) alone and in combination in 16 patients with effort angina. The 16 patients (13 men and three women; mean age 59 +/- 7 years) performed a symptom-limited bicycle exercise stress test 3 h after placebo or active substance administration. Maximal work load, exercise duration and time to 1 mm ST segment depression were significantly increased and ST depression at peak exercise was significantly decreased by the combination of drugs. Nifedipine and diltiazem alone similarly improved exercise duration as markedly as their combination. One patient stopped the test after all three treatments for angina associated with ST depression > 2 mm. The combination of drugs yielded the best symptomatic effect: only four patients complained of angina in comparison to eight and seven patients after diltiazem and nifedipine, respectively. Nifedipine and diltiazem are effective and safe antianginal drugs. Some patients respond better to one drug than to the other. Patients who remain symptomatic in spite of maximal doses of a single drug may derive some benefit from combination therapy.