Benefits of Short- and Long-Term, Maximally Tolerated Diltiazem Therapy for Chronic Effort Angina in Patients Receiving Long-Term Nitrates

The safety and efficacy of maximally tolerated doses of oral diltiazem were evaluated in both short-term (Phase I, 14 weeks) and long-term (Phase II, 46 weeks) periods in 15 patients with chronic, stable effort angina who were taking long-acting nitrates throughout the study. Both phases were designed to compare the effects of diltiazem against placebo in a double-blind, crossover fashion. Thirteen of the 15 patients tolerated the maximum diltiazem dosage (360 mg/day). No patient had intolerable aggravation of angina after an abrupt discontinuation of diltiazem encountered in the double-blind segments. Serial treadmill testing documented the increase in time to onset of angina, time to appearance of 1-mm ST segment change, and total exercise duration in both double-blind phases with diltiazem plus nitrate compared with placebo plus nitrate (P