It is a very potent loop diuretic, inhibits water reabsorption in the nephron by blocking the Na⁺ K⁺-2Cl⁻ cotransport (NKCC2) in the thick ascending limb of the loop of Henle. This is achieved through competitive inhibition at the chloride binding site on the cotransporter, thus preventing the transport of sodium from the lumen of the loop of Henle into the basolateral interstitium. Consequently, the lumen becomes more hypertonic while the interstitium becomes less hypertonic, which in turn diminishes the osmotic gradient for water reabsorption throughout the nephron.
Fluid electrolyte imbalance, blurred vision, dizziness, photosensitivity, bone marrow depression, glycosuria, hyperglycemia, ototoxicity, hypotension, anorexia and excessive urination
Renal and hepatic disease, gout, impaired micturation, pregnancy, lactation,
Adult: 40-80mg daily, alone or in combination with other antihypertensive
Child: 1-3 mg/kg daily
Oedema associated with heart failure
Adult: Initially, 20mg daily or 40 mg every other day for mild case, or 40mg once daily adjusted according to response