Potassium-sparing diuretics

Question 1

Mechanism of action of spironolactone and

eplerenone

Answer 1

Prevents K+ secretion by antagonizing effects of aldosterone at the late distal and cortical collecting duct

Question 2

Mechanism of action of amiloride, triamterene

Answer 2

Inhibits Na+ influx thru ion channels in the luminal membrane

Question 3

Side effects

Answer 3

1. Hyperkalemia in patients with compromised renal function
2. gynecomastia
3. menstrual irregularities (amenorrhea) due to antiandrogenic effects

Question 4

A potassium sparing diuretic which acts on the distal tubule to inhibit sodium flux across the cell membrane and reduces potassium and hydrogen excretion

Answer 4

Triamterene

Question 5

Potassium-sparing diuretics are indicated for patients with?

Answer 5

1. Mineralocorticoid excess

2. Secondary hyperaldosteronism

Question 6

Toxicity of potassium sparing diuretics will cause:

Answer 6

1. Hyperkalemia

2. Hyperchloremic metabolic acidosis