A Multicenter Comparison of Isradipine and Felodipine in the Treatment of Mild-to-Moderate Hypertension

The objective of this study was to compare the tolerability of isradipine and felodipine in patients with mild-to-moderate hypertension. Following a 4-week placebo run-in, 143 patients entered a 12-week double-blind multicenter study. Patients were randomized to receive either isradipine (n = 72) or felodipine (n = 71) at a dose of 2.5 mg twice daily. Dose-doubling and the addition of enalapril (2.5 mg once daily) was permitted if diastolic blood pressure (DBP) was > 90 mm Hg at weeks 4 and 8, respectively. Isradipine reduced blood pressure from 165/104 +/- 13/6 mm Hg at baseline to 144/88 +/- 13/8 mm Hg at week 12 (P < .001) whereas felodipine reduced blood pressure from 171/104 +/- 17/6 mm Hg at baseline to 150/92 +/- 19/9 mm Hg at week 12 (P < .001). Similar incidences of headache, flushing, dizziness and tachycardia were reported in both groups. However, the incidence of ankle edema was significantly lower in the isradipine group (14% v 30%) (P = .028). It is concluded that isradipine represents a practical improvement over felodipine in the treatment of hypertension.