 Aliskiren is the first direct renin inhibitor approved by the FDA for the treatment of hypertension. It is a very specific and potent inhibitor of human renin. As such it may offer an advantage over ACE-I and ARB therapy as it blocks the rate limiting step of the RAS. It does not show a compensatory increase in RAS activity noted with ARBs or non-ACE production of Ang 2 as seen with ACE-Is. Aliskiren appears to have additive blood pressure lowering effects when added to ACE-I or ARB therapy. 