COMPARISON OF THE EFFICACY AND SAFETY OF ONCE-DAILY VERSUS TWICE-DAILY FORMULATIONS OF DILTIAZEM IN THE TREATMENT OF SYSTEMIC HYPERTENSION

The efficacy and safety of optimally titrated once-daily (CD) and twic e-daily (SR) diltiazem were compared in 111 patients with mild to mode rate systemic hypertension [seated diastolic blood pressure (DBP) grea ter than or equal to 95 mmHg and less than or equal to 114 mmHg] in a multicenter, randomized, double-blind, placebo run-in, parallel-group trial. Following a 4 week washout and placebo-controlled run-in period , patients were randomized to receive diltiazem CD 180 mg and matching placebo (n = 54), or diltiazem SR 90 mg bid (n = 57). Total daily dos es were titrated from 180 mg to 360 mg to achieve a goal of seated DBP <90 mmHg during a 6 week titration period. The patients continued to receive their optimal dose for a 6 week follow-up period. Ninety-six ( 96) patients (diltiazem CD: 47, diltiazem SR: 49) completed the study protocol, with 60% of the diltiazem CD and 55% of the diltiazem SR pat ients achieving the goal of seated DBP of <90 mmHg (p = 0.685). Althou gh significant decreases occurred in seated and standing measurements of diastolic and systolic BP and heart rate with treatment in both gro ups, there were no significant differences between treatment groups, B oth medications were well tolerated, with a similar frequency of adver se effects [diltiazem CD: 24/54 (37%) patients; diltiazem SR: 24/57 (4 2.1%) patients] with the most frequently reported adverse effects bein g headache and edema.