Loop diuretics

Question 1

examples include

Answer 1

FUROSEMIDE AND BUMETANIDE

Question 2

Mechanism of action

Answer 2

blocks the Na/K/2Cl triple co-transporter in the thick ascending loop of henle

Question 3

in the thick ascending loop of henle

Answer 3

• sodium, potassium and chloride get re-absorbed
• some of the re-absorbed potassium within the cell leaks back out through potassium channels into the tubule which generates a positive charge in the tubule which produces an electrical driving force allowing the para-cellular re-absorption of calcium and magnesium

Question 4

loop diuretics therefore stop re-absorption of

Answer 4

sodium, potassium, chloride, calcium and magnesium

hence increasing the solute concentration of the filtrate reducing the re-absorption of water

Question 5

pros of loop diuretics

Answer 5

• well absorbed from the GI tract
• rapid onset following IV administration
• effective in severe renal failure

Question 6

loop diuretics are used in

Answer 6

acute pulmonary oedema, congestive heart failure, nephrotic syndrome, ascites caused by hepatic cirrhosis, hypercalcaemia

Question 7

cons of loop diuretics

Answer 7

• hypocalcaemia
• hypomagnasaemia
• hypokalaemia (corrected using potassium supplementation or use a potassium spring diuretic instead)
• acute hypovolaemia
• ototoxicity
• hyperuricaemia- loop diuretics compete with transports of uric acid inhibiting its secretion
• metabolic alkalosis caused by increased hydrogen ion secretion
• metabolic alkalosis= caused by increased hydrogen ion secretion from the intercalated cells in the collecting tubule