What is the method of action of Loop diuretics?

inhibiting the Na-K-Cl cotransporter (NKCC) in the thick ascending limb of the loop of Henle, reducing the absorption of NaCl

What is the main clinical use of Loop diuretics?

• heart failure
• resistant hypertension

What are the main adverse effects of Loop diuretics?

• hypotension
• hyponatraemia
• hypokalaemia, hypomagnesaemia
• hypochloraemic alkalosis
• ototoxicity
• hypocalcaemia
• renal impairment (from dehydration + direct toxic effect)
• hyperglycaemia (less common than with thiazides)
• gout

Why might patients with poor renal function need higher doses of loop diuretics to have the same effect?

loop diuretics work on the apical membrane so they must first be filtered into the tubules by the glomerulus before they can have an effect