Angiotensin-converting enzyme inhibitors (ACE inhibitors) and angiotensin II receptor blockers (ARBs) are widely used antihypertensive agents which block the renin-angiotensin-aldosterone system (RAAS). They also have a role in delaying the progression of chronic kidney disease. By they have an inherent disadvantage of feed back increase in plasma renin activity. Aliskiren is novel agent which inhibits renin, the first limb of the RAAS. Aliskiren may have more renoprotective effects compared to ACE inhibitors and ARBs. Studies in animals have shown improved surivival and decreased renal injury with aliskiren. It has been shown that it can be safely used in chronic kidney disease (CKD) in humans for control of hypertension. Aliskiren has also been shown to decrease albuminuria when added to losartan in patients with early diabetic nephropathy in a randomized clinical trial. What remains to be proved are the effects of aliskiren on the hard renal end points and cardiovascular events. Aliskiren has also been reported to cause hyperkalemia like the ACE inhibitors and ARBs, especially when combined with agents like spironolactone, in the presence of unrecognized underlying CKD. Renin is the rate limiting step in RAAS and inhibition of renin with direct renin inhibitors (DRIs) seems to have a potential in preventing the progression of CKD. A combination of aliskiren with ACEI or ARB may be better tolerated than a combination of ACEI with an ARB. We need more large scale randomised clinical trials for further evaluating the benefits and disadvantages if any, of aliskiren as a novel renoprotective agent.
Recently FDA has issued a safety warning regarding the rare possibility of angioedema with aliskiren, which can occur in those with or without a history of angioedema with ACE inhibitors. This can be rarely fatal if involving the upper airway and needs close observation and immediate treatment http://www.fda.gov/Safety/MedWatch/SafetyInformation/ucm215535.htm).