Comparative Trial of Felodipine and Nifedipine in Refractory Hypertension

The aim of this study was to compare the new vasodilator felodipine with nifedipine in 18 patients with poorly controlled hypertension. The design was a double-blind, cross-over study using a double-dummy technique. Felodipine 5mg was given 3 times daily and nifedipine 10mg 3 times daily. In case of an unsatisfactory blood pressure reduction, the drug dose was doubled. 14 patients had the higher dose of felodipine and 16 the higher dose of nifedipine. Both agents had good antihypertensive effect. After 1 week's therapy, felodipine reduced the blood pressure by 18/12 mm Hg (supine) and 18/13 mm Hg (upright), and nifedipine by 19/11 and 24/14 mm Hg, respectively. After 4 weeks' therapy, 12 hours after drug intake, felodipine reduced the blood pressure by 11/8 mm Hg (supine) and 16/8mm Hg (upright), and nifedipine by 3/2 and 6/4 mm Hg, respectively. Two patients on nifedipine withdrew from the study due to adverse reactions. In general, however, there were few side effects, with no significant difference between the drugs.