Amlodipine and Loop Diuretics as the Second Anti-Hypertensive Medication for the Treatment of Hypertension with Chronic Kidney Diseases

Renoprotective effects of renin-angiotensin system inhibitors are well known. However, hypertension with chronic kidney diseases (CKDs) is usually hard to manage with a single agent, and requires the addition of either a calcium antagonist or diuretics to achieve the goal of blood pressure (BP) lowering. Retrospective study was performed among the patients who regularly visited our office, and whose BP had not reached the goal of BP despite of treatment with an angiotensin receptor blocker. Clinical parameters were observed for 6 months. Comparisons of home BP and proteinuria were made between 16 patients prescribed additional calcium antagonists and 15 patients with diuretics. Patient background including age, sex BP, augmentation index, and renal function were similar between the two groups. Both calcium antagonists and diuretics considerably decreased BP. An addition of either agent resulted in similar control of home BP. While both agents reduced augmentation index (AI), calcium antagonist exerted greater improvements in AI (-7 +/- 5 vs. -4 +/- 3%, p < 0.01). Although urinary protein excretion in both groups was decreased, the degree of these decreases was greater among the patients treated with a calcium antagonist (-28 +/- 15 vs. -11 +/- 15%, p < 0.01). During observation periods, eGFR in both groups did not show any significant changes from the base line. Under the inhibition of a renin-angiotensin system, calcium antagonists elicited a greater decrease in urinary protein excretion than diuretics when BP similarly controlled. Calcium antagonists also improved AI more strongly than diuretics. Calcium antagonists appear suited for adding on renin angiotensin system inhibitors to treat hypertension with CKDs.