Aliskiren: a novel renoprotective agent or simply an alternative to ACE inhibitors?

Chronic kidney disease (CKD) is a common condition that is increasing in prevalence in developed nations. The economic and psychosocial costs of CKD are considerable, and are associated with high levels of morbidity and mortality. Specific treatments do not exist for many causes of CKD. Therefore, treatment is reliant on the introduction of therapies that retard progression of structural renal damage and renal impairment. At present, aside from judicious use of antihypertensive agents to lower blood pressure, and possibly low-protein diets and statin therapy, blockade of the renin-angiotensin-aldosterone system (RAAS) with angiotensin-converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs) are the only widely available treatments. Although these measures attenuate the inexorable progression to renal failure, they do not halt it. One limiting factor may be feedback effects of ACEis and ARBs, such as increased plasma renin activity. Aliskiren is a newer agent that inhibits renin, the rate-limiting step in the RAAS. There are several theoretical reasons to suggest that aliskiren may have renoprotective actions superior to those of ACEis and ARBs. In this paper the available evidence regarding renoprotective effects of aliskiren is reviewed, with an emphasis on comparison with ACEis and ARBs.