Safety of enhanced renin–angiotensin–aldosterone system inhibition with aliskiren in nondiabetic patients with chronic kidney disease

INTRODUCTION: Various methods of combination renin-angiotensin-aldosterone system blockade help achieve more potent antiproteinuric effects, but may be associated with higher risk of side effects. Therapies involving direct renin inhibitor, aliskiren, may promote renal fibrosis by stimulating (pro)renin receptor due to increased renin levels. OBJECTIVES: The aim of the study was to compare the effects of combination treatment with angiotensin receptor blockers, telmisartan (80 mg/d) and aliskiren (300 mg/d) with those of combination treatment with 80 mg/d telmisartan and mineralocorticoid receptor blocker (50 mg/d eplerenone) and telmisartan (160 mg/d) alone on the urinary excretion of transforming growth factor β1 (TGF‑β1), renal function, and serum potassium levels. PATIENTS AND METHODS: A randomized open-label controlled cross-over study was performed in 18 white patients (7 women and 11 men; mean age, 42.4 ±1.9 years) with proteinuric nondiabetic chronic kidney disease and estimated glomerular filtration rate of 85.2 ±4.6 ml/min. RESULTS: The urinary excretion of TGF‑β1 was stable despite a significant increase in plasma renin levels after treatment with telmisartan and aliskiren. There were no differences in renal function and serum potassium levels between the compared treatments. Moreover, there were no episodes of hypotension or acute renal impairment. CONCLUSIONS: Combination therapy with telmisartan and aliskiren may be safe in young nondiabetic patients with normal renal function at low vascular risk. This treatment may be an alternative for a subset of patients in whom standard RAA system blockade is ineffective.