Loop diuretics

What are Loop diuretics?

Diuretics are medicines that increase urine flow (cause diuresis). Loop diuretics are a powerful type of diuretic that work by inhibiting the sodium-potassium-chloride (Na+/K+/2Cl) co-transporter in the thick ascending loop of Henle (hence the name loop diuretic), which is located in the kidneys. 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.

Loop diuretics are used in the treatment of edema due to heart failure, liver disease and kidney disease. They may also be used to treat high blood pressure.

The most commonly used loop diuretics are furosemide, bumetanide, and torsemide, which are sulfonamide derivatives. Ethacrynic acid is rarely used but is an alternative in patients who have a hypersensitivity reaction to a typical loop diuretic.

Diuretics are drugs that increase the flow of urine. They are commonly used to treat edema, hypertension, and heart failure. Typically, the pharmacological group consists of five classes: thiazide diuretics, loop diuretics, potassium-sparing diuretics, osmotic diuretics, and carbonic anhydrase inhibitors.

Consequently, loop diuretics commonly cause flow-induced K⁺ secretion at the CNT and CD. This secondary effect of loop diuretics leads to their K⁺-wasting action. This is the reason why K⁺ supplementation is often required when treating with loop diuretics.