• Loop diuretics decrease the kidney’s ability to absorb sodium, causing more sodium to be eliminated through urine. Loop diuretics produce the greatest increase in urine flow. They may be administered through an intravenous (I.V.) line in the hospital to reduce swelling (edema) in patients with a variety of conditions (e.g., heart failure). They are most commonly used as oral medications.

  • Thiazide (or thiazide-like) diuretics increase the excretion of both sodium and chloride into the urine. They are commonly prescribed for heart patients, either alone or in conjunction with a potassium-sparing version. They are also commonly used to treat high pressure blood (hypertension). These drugs have been shown to reduce calcium excretion, meaning they are attractive options for patients with kidney stones or osteoporosis.

  • Potassium-sparing diuretics are used to protect the body from excess potassium loss, which can occur with loop and thiazide diuretics. Far less potent, potassium-sparing diuretics are commonly used in conjunction with the other forms of diuretics. They are also frequently used in patients with liver disease and ascites (fluid build-up in the abdomen due to liver damage). In addition, they can be used to treat high blood pressure and low potassium levels.

  • Osmotic diuretics are the least used form of diuretics. They draw fluid from the cells of the brain and eyes, as well as increase the elimination of toxins introduced into the body (from legal or illegal drugs) through urine. The mechanic process involves the increase of osmotic pressure (ion concentration) in blood and blood vessels, inhibiting the reabsorption of water and dissolved substances, and causing an increase in urine flow.