Research Area: Cardiovascular Disease Biological Activity: Furosemide(Lasix) is a loop diuretic used in the treatment of congestive heart failure and edema. Furosemide acts by inhibiting the Na-K-2Cl symporter in the thick ascending limb of the loop of Henle. The action on the distal tubules is independent of any inhibitory effect on carbonic anhydrase or aldosterone; it also abolishes the corticomedullary osmotic gradient and blocks negative as well as positive free water clearance. [1]