Graded extended-release diltiazem (CARDIZEM" LA) (GRD) is a new formulation of diltiazem engineered to provide more precise blood pressure control than traditional antihypertensive agents. Unlike other diltiazem once-daily formulations, CARDIZEM" LA is a tablet formulation. Its pharmacokinetic profile differs from that of CARDIZEM" CD, another extended-release formulation of diltiazem, in that GRD exhibits a smoother drug-release profile with a "one-peak" plasma concentration time curve. Clinical results demonstrate therapeutic efficacy throughout its 24-h dosing interval, regardless of time of administration; however, compared with morning administration, evening dosing results in significantly greater bioavailability. The trial results, demonstrating consistent 24-h efficacy and excellent tolerability, suggest that GRD may be a beneficial option in the treatment of hypertension and angina.