Better renoprotective effect of angiotensin II antagonist compared to dihydropyridine calcium channel blocker in childhood.

Background: The dihydropyridine calcium channel blocker amlodipine and the angiotensin II antagonist irbesartan effectively reduce blood pressure in hypertensive children.

Methods: Eligible for the open-label, randomized study were nephropathic children between 6.0 and 18 years of age with plasma creatinine <177 micromol/L, overt proteinuria, untreated arterial hypertension (systolic, 5 to 30 mm Hg; and diastolic, 1 to 15 mm Hg;>95th centile) and stable immunosuppressive treatment. The initial dose of amlodipine was 5 mg (body weight, 20 to 40 kg) and 10 mg (body weight,>40 kg), respectively, that of irbesartan, which was 75 mg (body weight, 20 to 40 kg) and 150 mg (body weight,>40 kg), respectively. The dosage was doubled if necessary.

Results: A total of 26 children aged 6.1 to 17 years were allocated to receive either amlodipine (N = 13) or irbesartan (N = 13) for 16 weeks. Severe edema and headache occurred in two patients on amlodipine who withdrew from the study. No adverse experiences were noted in patients given irbesartan. Amlodipine [by 12 (10 to 14)/7 (5 to 10) mm Hg; median and interquartile range, respectively] and irbesartan [by 13 (9 to 16)/9 (7 to 11) mm Hg, respectively] reduced blood pressure (P < 0.01) in a similar fashion. Heart rate, plasma sodium, and creatinine did not change. Irbesartan slightly increased plasma potassium [by 0.1 (0.0 to 0.2) mmol/L; P < 0.05]. Plasma albumin and the urinary albumin/creatinine ratio were similar before and with amlodipine. On the contrary, irbesartan increased plasma albumin [by 4 (3 to 5) g/L; P < 0.03] and decreased the urinary albumin/creatinine ratio [by 242 (68 to 312) mg/mmol; P < 0.03].

Conclusion: The study demonstrates that in children the effect of angiotensin II antagonists on proteinuria is better than that of dihydropyridine calcium channel blockers.