Bumetanide is a loop diuretic drug, administered orally or intravenously the treatment of edema associated with congestive heart failure, hepatic and renal disease including the nephrotic syndrome. It targets the nephrons of the kidney, mainly the ascending limb of the loop of henle. The basolateral membrane of the ascending loop of henle contains the Na+/K+ ATPase, Cl- channel and K+/Cl- co-transporter which are essential for the function for ion and water reabsorption. The Na+/K+ ATPase pumps Na+ from the cell into the peritubular fluid and K+ from the peritubular fluid into the cell. The K+/Cl- co-transporter moves K+ and Cl- from the cell into the peritubular fluid and the Cl- channel transports Cl- from the cell into the peritubular fluid. The apical membrane contains the Na+/K+/2Cl- co-transporter (NKCC2) and the K+ channel. The NCKCC2 is responsible for reabsorption Na+, K+ and Cl- from the lumen into the cells of the loop of henle. The K+ channel transports K+ from the cells back into the lumen. Bumetanide is transported from the capillaries into the cells of the loop of henle then transported from the cell into the lumen. Bumetanide binds to NKCC2 transporter and inhibits it, preventing Na+, K+ and Cl- reabsorption from the lumen. The concentration of these ions builds up in the lumen, decreasing the slope of the concentration gradient between the cells and the lumen. Since water reabsorption is linked to ion reabsorption, water reabsorption is also decreased, resulting in a greater volume of water being excreted in urine. This is relieves symptoms such as swelling/ edema in patients. Side effects such as peeing more than normal, feeling thirsty and dry mouth, losing a bit of weight (as your body loses water), headaches, feeling confused or dizzy, muscle cramps or weak muscles may occur when taking bumetanide.

Bumetanide Diruretic Pathway References