What effect does Furosemide have on potassium levels?

Furosemide is a loop diuretic that primarily acts on the ascending limb of the loop of Henle in the nephron, inhibiting the sodium-potassium-chloride cotransporter. This action promotes the excretion of sodium, chloride, and water, which can lead to a loss of potassium as well. Furosemide increases renal potassium excretion, resulting in a decrease of potassium levels in the blood, known as hypokalemia.

This occurs because as the diuretic enhances the flow of urine, there is less time for potassium to be reabsorbed in the renal tubules, leading to increased potassium loss. Therefore, patients on furosemide often require monitoring of potassium levels and may need potassium supplementation to prevent hypokalemia.

The other situations listed, such as hyperkalemia or no effect on potassium levels, do not accurately describe the expected physiological outcome when furosemide is used. In addition, acidosis is not directly caused by the use of furosemide; it primarily influences acid-base balance through mechanisms unrelated to potassium levels.