A comparison of candesartan, felodipine, and their combination in the treatment of elderly patients with systolic hypertension

Abstract

Monotherapy frequently does not cause adequate blood pressure (BP) reduction and goal BP is not achieved. This double-blind, randomized, crossover, placebo-controlled study investigated, using a factorial design, the interaction between a dihydropyridine calcium channel blocking drug (felodipine 5 mg) and an angiotensin type I receptor blocking drug (candesartan 16 mg) on the control of BP as assessed by 24-h ambulatory monitoring. A total of 31 elderly patients with systolic hypertension completed all four arms of the study. Candesartan and felodipine lowered mean 24-h BP to a similar extent (candesartan 12.2 +/- 2.6/7.5 +/- 1.8; felodipine 11.9 +/- 2.2/5.7 +/- 1.4 mm Hg). The combination lowered it by 21.0 +/- 2.1/11.2 +/- 1.2 mm Hg, and this fall was significantly greater than with either of the monotherapies (P < .005) and was fully additive with no interactive term. The responder rate with the combination (90%) was greater than with candesartan (61%) or felodipine (55%). Microalbuminuria or proteinuria was present in 12 of 31 patients at randomization despite previous BP control. Candesartan and the combination both reduced urinary albumin excretion. Albumin excretion was not reduced by felodipine despite BP control similar to that achieved with candesartan. Side effects were infrequent and were fewer on the combination than on placebo or on the monotherapies. The combination of felodipine 5 mg and candesartan 16 mg has additive effects on BP in elderly patients with systolic hypertension. The combination was well tolerated and is suitable for use in patients who do not have an adequate response to monotherapy.