Felodipine extended-release tablets once daily are equivalent to plain tablets twice daily in treating hypertension. Dutch Hospital Multicentre Group.

The efficacy of and tolerance to felodipine given as extended-release (ER) tablets once daily (o.d.) and the plain tablets twice daily (b.i.d.) were compared in this study. After a 4-week period on placebo and a beta-blocker, 102 patients who had a diastolic blood pressure (DBP) in the supine position greater than 95 mm Hg were randomized to treatment with felodipine ER tablets 10 mg o.d. (n = 50) or plain tablets 5 mg b.i.d. (n = 52). If the DBP was greater than 90 mm Hg after 2 weeks, the dose was doubled. The total treatment time on felodipine was 6 weeks. Blood pressure (BP) was measured 2 h after the dose and at the end of the dosing interval, i.e., 24 h after ER and 12 h after plain tablets. Both formulations reduced BP significantly (15/12 mm Hg in the ER and 13/11 mm Hg in the plain tablet group, at the end of the dosing interval). No differences in BP reduction were seen between the groups. The proportion of responders was 71% on ER and 65% on plain tablets 24 and 12 h, respectively, after dose intake, and greater than 90% in both groups, when measured 2 h after dose. Ankle swelling and flushing were the most frequently reported adverse events. Eight patients (three on ER) were withdrawn, most of them due to vasodilatory side effects. Felodipine ER once daily was as effective and tolerable as plain tablets b.i.d.