24-HOUR BLOOD-PRESSURE CONTROL WITH ONCE-DAILY VERSUS TWICE-DAILY FORMULATIONS OF DILTIAZEM

The antihypertensive effects of once-daily diltiazem CD over a 24 hour period were compared with twice-daily diltiazem SR in 95 patients wit h mild to moderate hypertension using ambulatory blood pressure monito ring. This trial was designed as a multicenter, double-blind, parallel -group study. Following a 2 to 4 week placebo run-in period, diltiazem was administered as once-daily CD or twice-daily SR, starting with 18 0 mg daily and increasing to a maximum of 360 mg daily, to achieve a s eated diastolic blood pressure goal of less than or equal to 90 mmHg a s measured by cuff between 08:00 and 10:00 in the morning. Following d rug titration, patients received a maintenance dose of diltiazem for a n additional 6 week follow-up phase. Twenty-four hour ambulatory blood pressure monitoring recordings were obtained at the end of the placeb o, titration, and maintenance phases. Both diltiazem CD and diltiazem SR significantly reduced both systolic and diastolic blood pressure ov er the 24 hour day and maintained a normal circadian pattern. As well, treatment with once-a-day diltiazem CD significantly decreased the sl ope of the early morning rise of diastolic and mean blood pressure. Th us, diltiazem CD is as effective as diltiazem SR in lowering diastolic : blood pressure over a 24 hour period and has the advantage of a once -daily formulation.