Angiotensin Receptor Blockers are also known as Angiotensin II receptor antagonists and are mediated by Renin-Angiotensin-Aldosterone-System (RAAS). ARB’s like Aliskiren reduces blood pressure by direct renin inhibition and causes a net reduction in plasma renin activity, angiotensin II and aldosterone levels. Angiotensin II is a very potent chemical formed in the blood that causes muscles surrounding blood vessels to contract, thereby narrowing the vessels. This narrowing increases the pressure within the vessels and can cause high blood pressure (hypertension). ARBs are used alone or in combination with other drugs for controlling high blood pressure. They also are used for treating congestive heart failure, preventing diabetes or high blood pressure-related kidney failure, and reducing the risk of stroke in patients with hypertension. Many drugs control blood pressure by interfering with angiotensin or aldosterone. However, when these drugs are used chronically, the body increases renin production. Aliskiren has been used in combination with angiotensin converting enzyme inhibitor (ACE-I) or angiotensin receptor blockers (ARBs) to reduce blood pressure to target values via a synergistic blockade of the reninangiotensin system (RAS).