What is the MOA of furosemide?

Furosemide is classified as a loop diuretic, and its primary mechanism of action involves the inhibition of the Na/2Cl/K pump located in the thick ascending limb of the loop of Henle in the nephron. By blocking this symporter, furosemide prevents the reabsorption of sodium, chloride, and potassium ions from the renal tubular fluid back into the blood. This leads to increased sodium and water excretion, thereby producing an osmotic diuresis.

The significance of this mechanism lies in its effectiveness in managing conditions associated with fluid overload, such as congestive heart failure, pulmonary edema, and certain kidney disorders. Due to its potent action, furosemide can result in significant diuresis, making it a crucial medication in veterinary and human medicine.

The other options propose mechanisms that do not accurately describe how furosemide works. While bicarbonate reabsorption, aldosterone antagonism, and the presence of non-absorbable solutes can play roles in renal function and fluid balance, they do not represent the specific pathway through which furosemide exerts its diuretic effect.