Antihypertensive Drugs
How Antihypertensive Drugs Work High blood pressure (hypertension) is a complex condition influenced by multiple physiological systems: blood vessel tone, fluid volume, heart function, and neurohormonal signaling (renin-angiotensin, sympathetic nervous system, etc.). Because there is no single “cause” of hypertension, different drug classes target different parts of the system to lower blood pressure. Here are the main mechanisms by which antihypertensive agents act: Vasodilation / relaxing blood vessels. Many drugs reduce vascular resistance by relaxing smooth muscle in the walls of arteries and arterioles. This lowers the force the heart must pump against. ACE inhibitors, angiotensin II receptor blockers (ARBs), and calcium channel blockers all act (in part) via this mechanism. Reducing blood volume (diuresis / natriuresis). Diuretics increase the excretion of sodium and water through the kidneys, reducing total circulating fluid volume and lowering blood pressure....