Aliskiren

Aliskiren is a renin inhibitor. Renin is secreted by the kidneys when blood volume and renal perfusion decrease. It normally cleaves the protein angiotensinogen to form angiotensin I. Angiotensin I is then converted to angiotensin II, an active protein. Angiotensin II is a potent vasoconstrictor that causes the release of catecholamines into the circulation. It also promotes the secretion of aldosterone in addition to sodium reabsorption, increasing blood pressure. Additionally, angiotensin II acts on the adrenal cortex where it stimulates aldosterone release. Aldosterone increases sodium reabsorption and potassium excretion in the nephron.

Aliskiren prevents the above process via binding to renin at its active site, stopping the cleavage of angiotensin, in turn inhibiting the formation of angiotensin I. This ends the cascade of angiotensin II mediated mechanisms that normally increase blood pressure.