CV meds - Aldersterone Antagonists

Question 1

Give 3 indications for aldersterone antagonists (spironolactone, epelrenone)
Which indication do these drugs work best?

Answer 1

1. Chronic heart failure - usually in addition to a beta-blocker & ACEi/ARB
2. ascites and oedema due to liver cirrhosis - spiro 1st line
3. primary hyperaldersteonism/ Conns syndrome/ make too much aldersterone - while awaiting surgey or of surgery not an option
   - work best for cirrhosis or hyperaldersteonism (this is when aldersterone levels are highest)

Question 2

what type of steroid is aldersterone and where is it produced and where does it act?
what efect does this have on the body?
what happens to K+?

Answer 2

• mineralocorticoid
• adrenal cortex
• acts on mineralocorticoid receptors in distal tubules of kindey
• increases activity of luminal epithelial Na+ channels = increased reabsorption on Na+ & water = increase BP
• K+ excretion increased

Question 3

How do aldersterone antagonisists work?
- type of inhibition, location, effect

Answer 3

• competitive inhibitors of aldesterone
• at mineralsocorticoid receptors
• this increases Na+ and water excretion and K+ retention

Question 4

name 2 adverse effects of aldersterone antagonists and which one has less endocrine effects.

Answer 4

1. hyperkalaemia - leads to muscle weakness, arrhythmias, cardiac arrest
2. gynaecomastia - increase male breast tissue
   eplerenone is less likely to cause endocrine effects

Question 5

can aldersterone antagonists be used in pregnancy/breastfeeding?

Answer 5

can cross placenta so avoid is possible (do benefits outweigh risks) metabolites present in breastmilk

Question 6

name a contraindication of alderesterone antagonists

Answer 6

hyperkalaemia

Question 7

which aldersterone antagonist is just licensed for heart failure

Answer 7

eplerenone

Question 8

whats a key interaciton with aldersterone antagonists?

Answer 8

any potassium elevating drugs - ACEi, ARBs, K+ supplements

Question 9

whats the starting dose of spironolactone for ascites compared to heart failure ?

Answer 9

ascites - 100mg
heart failure - 25mg

Question 10

what are the key monitoring requirements for aldersterone antagonists?

Answer 10

serum potassium levels - also need to monitor renal function (BNF says avoid eGFR 30ml/min)

Question 11

spironolactone is quite a weak diuretic which takes several weeks to have an effect, what type of diuretic is often co-prescribed to potentiate the diuretic effect and counteract potassium wasting?

Answer 11

a loop or thiaizide diuretic