ANTIANGINAL EFFICACY AND SAFETY OF CONTROLLED-DELIVERY DILTIAZEM QD VERSUS AN EQUIVALENT DOSE OF IMMEDIATE-RELEASE DILTIAZEM TID

Controlled-delivery once-daily diltiazem (qd), 180 mg and 360 mg, was assessed in two multicenter, randomized, double-blind, placebo-control led trials using a 3 x 3 Latin square design. Both studies compared th e controlled-delivery dosage form to the same total daily dose of imme diate-release diltiazem administered three times daily (tid) and to pl acebo. The primary measure of efficacy was the time to termination of the exercise tolerance test (ETT) at 2, 8, and 24 hours after the morn ing dose. There were no significant differences in time to ETT termina tion between the qd and tid formulations at any time, except at 24 hou rs with 180 mg qd versus 60 mg tid. The comparison to placebo showed t hat diltiazem 180 mg qd, 360 mg qd, and 120 mg tid significantly lengt hened the time to ETT termination (p < 0.05) at all time points, while diltiazem 60 mg tid did not differ from placebo at any time point. Th e qd formulation also increased the time to 1-mm ST-segment depression and reduced the number of angina attacks and the amount of nitroglyce rin used when compared to placebo. No new or unusual adverse events we re noted. Diltiazem controlled-release capsules administered once dail y are safe and effective for the treatment of patients with chronic st able angina,