Twenty‐four hour efficacy of two dose levels of a once daily sustained‐ release diltiazem formulation in stable angina: a placebo‐controlled trial. The Dildurang Study Group.

Abstract

1. This placebo‐controlled study assessed once daily sustained‐release (SR) diltiazem, 200 and 300 mg, in 182 stable angina patients with positive exercise test. 2. Exercise testing was performed at baseline after a 7 day placebo run‐in period, and repeated after 7 days of treatment, 25.0 +/‐ 0.1 h postdose. 3. Diltiazem (200 and 300 mg) produced respectively a 68% and a 64% decrease in weekly angina episodes, and placebo a 15% decrease (P < 0.05). Similarly, both dose levels produced a 70% decrease in nitroglycerin consumption, whereas no difference was obtained with placebo (P < 0.01). The increase in time to ischaemic threshold was significantly superior for 200 mg and 300 mg diltiazem when compared with placebo (75.2 and 91.5 s respectively vs 47.0 s) (P < 0.05); increase in time to anginal threshold was also significantly greater for diltiazem when compared with placebo (84.6 and 85.9 s respectively vs 43.9 s) (P < 0.05). 4. Only one patient experienced worsening of angina and had to be withdrawn from the study. 5. This study demonstrates 200 and 300 mg SR diltiazem is effective when given once‐a‐day in the prophylaxis of stable exertional angina. This once daily formulation should improve patients' compliance and comfort. 1995 The British Pharmacological Society