Renal effects of felodipine in hypertension

The results of 2 recent studies on the renal effects of felodipine in hypertensive patients are described. Antihypertensive doses of felodipine (10mg bid) displayed a clear natriuretic and diuretic effect associated with a constant glomerular filtration rate and an increase in renal plasma flow. With higher doses of felodipine (up to 50mg tid), the natriuretic effect was reversed to an antinatriuretic effect, accompanied by a reduction in glomerular filtration rate. The natriuretic effect of felodipine 10mg bid was evident during the first 2 days of administration, but a negative sodium balance was still present at the end of the seventh day. The mechanisms of the renal effects of calcium antagonists are discussed as well as the relevance of the natriuretic effect for the antihypertensive action of these compounds.