Spironolactone in heart failure: what it is for
Which statement about spironolactone in heart failure is correct?
chevron_right Show answer and explanation
A. It is a potent diuretic that can replace furosemide in pulmonary oedema
At the doses used in cardiology its diuretic effect is weak and slow. It never replaces the loop diuretic in oedema; it is added to it.
B. Its benefit is mainly attributed to blocking the effects of aldosterone (fibrosis, remodelling), which remains elevated despite ACE inhibition
Correct. It is a mineralocorticoid receptor antagonist. Over time aldosterone rises again despite an ACE inhibitor ('aldosterone escape'), and blocking its action reduces myocardial and vascular fibrosis. That is why the ACVIM consensus includes it in stage C treatment.
C. It tends to cause hypokalaemia, so potassium should be supplemented
It is a potassium-sparing diuretic: it tends to raise potassium, especially with an ACE inhibitor or kidney disease. Routine potassium supplementation increases the risk of hyperkalaemia.
D. It has no described adverse effects in cats
Ulcerative facial dermatitis has been described in cats, particularly Maine Coons, which resolves on withdrawal. Its use in cats is less common and should be monitored.
lightbulb Key takeaway
Think of spironolactone as an 'anti-remodelling' drug added to furosemide, pimobendan and an ACE inhibitor in stage C, not as a rescue diuretic. Monitor potassium and renal function, especially if the patient has kidney disease or takes other potassium-retaining drugs.
Test yourself with 10 random questions
Cardiology · 100 questions, a different test every time
Related questions
Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.