Diuretics act on the kidney in order to help the excretion of water when its quantity in the body is above normal. The decrease in the volume of water in the body causes a reduction in the total volume of circulating blood, resulting in a decrease in blood pressure.
There are three classes of diuretics that are commonly used to treat high blood pressure: high ceiling loop diuretics, thiazides and potassium-sparing diuretics. All three inhibit the reabsorption of blood sodium and water, which leads to increased urinary volume. Since thiazide and high ceiling loop diuretic may lead to excessive loss of potassium, which may cause weakness, confusion, or cardiac arrhythmia, taking a potassium supplement may be indicated. Otherwise the doctor may prescribe a potassium-sparing diuretic which is softer and which prevents excessive loss of potassium, in combination with a thiazide or a high ceiling loop diuretic.
Diuretics are also prescribed to treat heart failure because they help eliminate swelling and reduce cardiac work.
See also: Diuretics.
Cardiovascular drug groups:
Diuretics | Beta Blockers | Calcium Channel Blockers | ACE Inhibitors | Centrally Acting Adrenergic Drugs | Peripherally Acting Adrenergic Drugs | Nitrates | Hypolipidemic Agents | Cardiac Glycosides | Antithrombotics