Antiproteinuric effect of the calcium channel blocker cilnidipine added to renin-angiotensin inhibition in hypertensive patients with chronic renal disease

Cilnidipine, a dual L-/N-type calcium channel blocker, dilates both efferent and afferent arterioles and is renoprotective. Our multi-center, open-labeled, and randomized trial compared the antiproteinuric effect of cilnidipine with that of amlodipine in hypertensive patients with kidney disease. A group of 339 patients, already receiving renin-angiotensin system inhibitor treatment, were randomly assigned to cilnidipine or amlodipine. The primary endpoint was a decrease in the urinary protein to creatinine ratio. After 1-year of treatment, systolic and diastolic blood pressures were significantly reduced in both groups which did not differ between them. The urinary protein to creatinine ratio significantly decreased in the cilnidipine compared to the amlodipine group. Cilnidipine exerted a greater antiproteinuric effect than amlodipine even in the subgroup whose blood pressure fell below the target level. This study suggests that cilnidipine is superior to amlodipine in preventing the progression of proteinuria in hypertensive patients when coupled with a renin-angiotensin system inhibitor.