Aldosterone antagonists Flashcards
What are aldosterone antagonists used for?
- Ascites and oedema - liver cirrhosis
- Chronic heart failure
- Primary hyperaldosteronism
What is an example of an aldosterone antagonist?
Spironolactone
How do aldosterone antagonists work?
Inhibit the effect of aldosterone by competitively binding to the aldosterone receptor. This increases sodium and water excretion and potassium retention.
What adverse reactions are associated with aldosterone antagonists?
- Hyperkalaemia
- Gynaecomastia
- Liver impairment
- SJS
When are aldosterone antagonists contraindicated for use?
- Severe renal impairment
- Hyperkalaemia
- Addison’s Disease
- Pregnancy or breastfeeding
What are important interactions to consider when using aldosterone antagonists?
Any drugs which can increase K+
- Potassium supplementation
- ACEi
- ARBs
How are aldosterone antagonists administered?
Oral administration
What dose of spironolactone would you use in someone with oedema/ascites in liver cirrhosis?
100-400 mg daily - adjusted to dose
What is the average starting dose for spironolactone when used?
100 mg once daily - can be less in certain circumstances (check bnf)
What starting dose for spironolactone is used in heart failure?
25mg
What drug can spironolactone sometimes be combined with?
Thiazide/loop diuretic
What advise would you give someone about taking spironolactone?
- Take with food
- Warn men of gynaecomastia and impotence
How would you monitor for an adverse effects of spironolactone?
Check renal function and serum potassium
Why is spironolactone given in combination with furosemide?
Spironolactone is a relatively weak diuretic that takes several days to start having an effect. It is therefore usually prescribed in combination with a loop or thiazide diuretic, where it both counteracts potassium wasting and potentiates the diuretic effect.
