Bumetanide-d is intended for use as an internal standard for the quantification of bumetanide by GC- or LC-MS. Bumetanide is an inhibitor of Na-K-2Cl cotransporter 1 (NKCC1; IC = 0.68 µM). It is selective for NKCC1 over NKCC2 (IC = 4 µM). Bumetanide is an agonist of G protein-coupled receptor 35 (GPR35; EC = 10 µM). It also inhibits various carbonic anhydrases. Bumetanide (0.1 mg/kg) increases urine flow and sodium and potassium excretion, as well as decreases sodium reabsorption, in anesthetized dogs. It reduces brain edema and infarct size in a rat model of stroke induced by permanent middle cerebral artery occlusion (MCAO) when administered at doses ranging from 7.6 to 30.4 mg/kg. Formulations containing bumetanide have been used in the treatment of edema associated with congestive heart failure and hepatic and renal diseases.