Background: Calcium channel blockers (CCBs) are effective blood pressure lowering agents, giving rise to a prevalent dilation of the afferent arteriole. Manidipine, a long-lasting dihydropyridine CCB, demonstrates its action not only on the afferent arteriole, but also on the efferent one. This suggests theoretically a renoprotective effect in patients with chronic kidney diseases (CKD).
Methods: This was a multicenter, prospective, randomized, double-blind, parallel group study, to evaluate the efficacy and tolerability of manidipine (M; 10-20 mg/day), in comparison with enalapril (E; 10-20 mg/day) in the treatment of hypertension in 136 patients with CKD secondary to primary renoparenchymal disease. Changes in blood pressure values from baseline were considered as the primary outcome of the study. Proteinuria changes and the rate of renal function decline were also evaluated.
Results: During a 48-week follow-up, mean SBP decreased from 155+/-11.7 to 138.7+/-13.9 mmHg in M and from 157.3 +/-11.8 to 134.2+/-13.9 mmHg in E; mean DBP decreased from 100.3+/-4.2 to 86.1+/-6.5 mmHg in M and from 100.3+/-4.2 to 84.7+/-6.3 mmHg in E. Proteinuria remained unchanged in M (from 1.6+/-1.59 to 1.62+/-1.79 g/24h), and decreased significantly in E (from 1.37+/-1.45 g/24h to 1+/-1.55 g/24h). No significant difference was observed in the rate of renal function decline in the two groups.
Conclusions: Manidipine was safe and effective, obtaining a significant reduction in SBP and DBP from baseline. Although patients treated with enalapril showed a better antiproteinuric response, the two treatments were equally effective in reducing the rate of CRF progression in patients without glomerular disease.