Comparison of candesartan and felodipine alone and combined in the treatment of hypertension: a single-center, double-blind, randomized, crossover trial.

BACKGROUND

In the past decade, many studies have indicated that the combination of low doses of different classes of antihypertensive agents may be more efficacious than monotherapy while minimizing the likelihood of dose-dependent adverse effects (AEs).

OBJECTIVE

The aim of this study was to determine whether combination therapy with lower doses of candesartan and a calcium antagonist, felodipine, would be more effective and tolerable in controlling mild to moderate hypertension compared with either drug used alone.

METHODS

In this 18-week, single-center, double-blind, crossover study, patients with mild to moderate essential hypertension were randomized to 1 of 2 treatment groups after a 2-week placebo washout period. Patients in group 1 received candesartan 16 mg once daily and patients in group 2 received felodipine 5 mg once daily, for 6 weeks. All patients then received half-dose combination therapy (candesartan 8 mg plus felodipine 2.5 mg, once daily) for 6 weeks. Finally, patients received 6 weeks of monotherapy with the alternate medication (group 1 received felodipine 5 mg once daily and group 2 received candesartan 16 mg once daily).

RESULTS

Thirty patients (18 men, 12 women; mean [SD] age, 54.0 [4.9] years; range, 39-62 years) were included in the study. During both monotherapy periods, candesartan and felodipine significantly reduced blood pressure (BP) (both P<0.001). BP further decreased with combination therapy (P<0.001 in both groups). Overall, 90.0% (27/30) of the patients achieved the target BP at the end of combination therapy. The incidence of AEs was similar with combination therapy compared with either monotherapy.

CONCLUSIONS

In this study population, candesartan and felodipine had additive effects when used in combination, even at low doses, in the treatment of hypertension. Therefore, the combination of candesartan and felodipine is an effective alternative to that of candesartan and hydrochlorothiazide.