Loop Diuretic Drugs

Diuretics are medicines that increase urine output, a process called diuresis. Loop diuretics are a powerful subgroup: they block the sodium-potassium-chloride (Na⁺/K⁺/2Cl⁻) co-transporter in the thick ascending limb of the loop of Henle in the kidney.

This reduces or abolishes sodium, chloride, and potassium reabsorption, leading to increased loss of sodium, chloride, and potassium into the nephron (the functional unit of a kidney). As a result, water is also drawn into the nephron and urine volume increases. Loop diuretics also reduce the reabsorption of calcium and magnesium.

Doctors use loop diuretics to relieve edema associated with heart failure, liver disease, or kidney disease, and they may also prescribe them to lower high blood pressure.