Furosemide & Spironolactone is a combination diuretic containing a loop diuretic, Furosemide and a potassium sparing diuretic, Spironolactone. Spironolactone and Furosemide have different but complementary mechanisms and sites of action. Therefore, when given together they produce additive or synergistic diuretic. The Furosemide component inhibits the Na+/K+/2Cl- co-transporter in the ascending Loop of Henle and blocks the reabsorption of sodium, potassium and chloride ions thereby increasing the quantity of sodium and the volume of water excreted in the urine. This characteristically induces potassium loss.