Diruetics

Question 1

Acetazolamide

Answer 1

Carbonic anhydrase inhibitor
Inhibits CA at the apical border and in cytoplasm of DCT
Prevents creation of HCO3- and therefore reabsorption of NaHCO3
Urine alkalosis and hypokalaemia
Weak

Question 2

Furosemide

Answer 2

Loop diuretic
Orally - venodilation in 10, diuretic in 1h. IV - diuretic in 10
V v potent- 10-25% of filtrate
Tolerance with repeated use
Blocks NaKCC transported in taLOH
Loss of all ions: hypokalaemia, alkalosis, calcium and magnesium loss
Gout

Question 3

Bumetadine

Answer 3

Loop diuretic
Orally - venodilation in 10, diuretic in 1h. IV - diuretic in 10
V v potent- 10-25% of filtrate
Tolerance with repeated use
Blocks NaKCC transported in taLOH
Loss of all ions: hypokalaemia, alkalosis, calcium and magnesium loss
Gout

Question 4

Hydrocholothiazide

Answer 4

Thiazide diuretic
Minor CA action and vasodilatory
Block NaCl transport at Cl binding site in DCT
Side effects: hypokalaemia, gout,
Increase Mg excretion, decrease calcium excretion

Question 5

Spironolactone

Answer 5

Potassium sparing mineralocorticoid antagonist diuretic

Acts on aldosterone receptors to inhibit up regulation of ENaC and NaKATPase, decreasing potassium efflux

Question 6

Amilodarone

Answer 6

Potassium sparing diuretic
Inhibits ENaC channel
Often combined with thiazides and loops

Question 7

Triamterene

Answer 7

Potassium sparing diuretic
Inhibits ENaC channel
Often combined with thiazides and loops

Question 8

Mannitol

Answer 8

Osmotic diuretic
Acts on PCT and DCT
Increases osmotic pressure of filtrate, preventing reabsorption of salt and water
Used to maintain urine flow and in cerebral oedema