24-HOUR EFFICACY OF 2 DOSE LEVELS OF A ONCE-DAILY SUSTAINED-RELEASE DILTIAZEM FORMULATION IN STABLE ANGINA - A PLACEBO-CONTROLLED TRIAL

1 This placebo-controlled study assessed once daily sustained-release (SR) diltiazem, 200 and 300 mg, in 182 stable angina patients with pos itive exercise test. 2 Exercise testing was performed at baseline afte r a 7 day placebo run-in period, and repeated after 7 days of treatmen t, 25.0 +/- 0.1 h postdose. 3 Diltiazem (200 and 300 mg) produced resp ectively a 68% and a 64% decrease in weekly angina episodes, and place bo a 15% decrease (P < 0.05). Similarly, both dose levels produced a 7 0% decrease in nitroglycerin consumption, whereas no difference was ob tained with placebo (P < 0.01). The increase in time to ischaemic thre shold 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 grea ter for diltiazem when compared with placebo (84.6 and 85.9 s respecti vely vs 43.9 s) (P < 0.05). 4 Only one patient experienced worsening o f angina and had to be withdrawn from the study. 5 This study demonstr ates 200 and 300 mg SR diltiazem is effective when given once-a-day in the prophylaxis of stable exertional angina. This once daily formulat ion should improve patients' compliance and comfort.