Loop Diuretics

Key points

• Furosemide and bumetanide inhibit the Na-K-Cl cotransporter (NKCC2) in the thick ascending limb of the loop of Henle, reducing absorption of NaCl
• Causes loss of water along with sodium chloride, potassium, calcium and hydrogen ions (hypercalciuria)
• Indications: heart failure — acute (usually intravenously) and chronic (usually orally) · resistant hypertension, particularly with renal impairment
• Adverse effects: hypotension · hyponatraemia · hypokalaemia, hypomagnesaemia · hypochloraemic alkalosis · ototoxicity · hypocalcaemia · renal impairment · hyperglycaemia (less common than with thiazides) · gout