Pathophysiology of Antihypertensive Therapy with Diuretics

Recent progress in antihypertensive therapy has widened the selection of drugs, and large clinical trials have attracted attention to newer classes of antihypertensives. Consequently, the use of diuretics as antihypertensive agents has been relatively reduced, particularly since the newer drugs are associated with fewer adverse metabolic reactions. However, diuretics have a specific activity of removing sodium from the body fluid, thereby rendering the blood pressure insensitive to sodium intake, relieving the overload to systemic circulation, and normalizing the circadian rhythm of blood pressure from a non-dipper to a dipper pattern. At low doses, diuretics are known to be as effective as all other antihypertensive agents for reducing nearly all types of cardiovascular events. In this brief review, the indication for thiazide diuretics will be discussed based on the pathophysiology of hypertension and antihypertensive therapy with diuretics mainly from the point of view of sodium metabolism. Low-dose diuretics will continue to be an important agent in the treatment of hypertension, mostly in combination with vasodilators such as modulators of the renin-angiotensin system and calcium channel blockers.