Diuretics

Question 1

Fx of proximal tubule

Answer 1

• majority of cation inc sodium absorption

- absorption of glucose, amino acids

Question 2

Fx of ascending loop of henle

Answer 2

• location of Na/K/Cl co transporter.

- site of calcium and mg reabsorption. 20% sodium

Question 3

Fx of distal tubule

Answer 3

• minimal sodium and calcium under control PTH

Question 4

Fx of collecting duct

Answer 4

• Na reabsorbed with equivalent excretion of K and H+ into urine
• urine acidification, potassium excretion

Question 5

MOA of loop diuretics

FUROSEMIDE, BUMETANIDE

Side effect

Answer 5

• block Na/K/2CL co transporter at ascending loop of henle
• significant loss of Na, K, Ca, H+
• hypokalaemia, metabolic alkalosis

Question 6

MOA thiazide

Bendroflumethiazide, metolazone

Answer 6

• inhibit NACL transporter at distal convulated tubules
• moderate loss of Na, Cl, K, increase Ca reabsorption

Side effect; high uric acid level

Question 7

MOA potassium sparring diuretics/ aldosterone antagonist

SPIRONOLACTONE

Answer 7

Block sodium channels in collecting duct, inhibiting potassium excretion and promoting sodium excretion