A Comparison of Isradipine and Felodipine in Australian Patients with Hypertension: Focus on Ankle Oedema

The aim of this study was to compare the tolerability and efficacy of isradipine and felodipine in the treatment of mild-moderate hypertension. After a 4 week placebo period, 143 patients entered a randomized, double-blind, multicentre study of 12 weeks duration. Patients received either isradipine (n = 72) or felodipine (n = 71) 2.5 mg twice daily. Doubling of this dose and the addition of enalapril (2.5 mg once daily) was permitted if DBP was > 90 mmHg at weeks 4 and 8, respectively. Isradipine monotherapy reduced BP from 165/104 +/- 13/6 mmHg at baseline to 149/91 +/- 14/10 mmHg at week 8 (p < 0.001), while felodipine alone reduced BP from 171/104 +/- 17/6 at baseline to 151/92 +/- 19/9 (p < 0.001). Following the addition of enalapril to 35% of patients in the isradipine group BP was further reduced to 144/88 +/- 13/8 mmHg at week 12 (p < 0.001). The addition of enalapril to 24% of the felodipine group further reduced BP to 150/92 +/- 19/9 mmHg at week 12 (p < 0.001). No differences in BP were found between the 2 groups while on monotherapy. However, the isradipine group had a significantly lower DBP than the felodipine group at the conclusion of the study (p = 0.008; 95% CI 0.7 to 6.9 mmHg). Similar incidences of headache, flushing, dizziness and tachycardia were reported in both groups. However, the incidence of ankle oedema was significantly lower in the isradipine group (p = 0.028). Overall, ankle oedema was reported more often by female patients and was not associated with an increase in weight.(ABSTRACT TRUNCATED AT 250 WORDS)