Loop Diuretics (Furosemide, Bumetanide, Torsemide)

Summary

Loop diuretics are powerful diuretics that include furosemide, bumetanide, and torsemide. These drugs work by inhibiting the sodium-potassium-chloride triple transporter in the ascending limb of the loop of henle. This decreases the medullary concentration gradient, preventing water reabsorption. The net effect of loop diuretics is increased excretion of water, sodium, and potassium. Because of their potent diuretic effects, loop diuretics are often used in the treatment of volume overload states as well as in the treatment of hypertension.  Important side effects to note include ototoxicity, sulfa allergy, as well as severe hypotension and hypovolemia, which may result in contraction alkalosis and even acute kidney injury! Because these drugs increase potassium excretion, loop diuretics are notorious for causing hypokalemia. Lastly, like most other diuretics, loop diuretics can increase uric acid levels to increase the risk of gout.