Spironolactone

Key points

• Potassium and kidney function need monitoring because dangerous hyperkalaemia can develop.
• Potassium supplements, salt substitutes and several heart or kidney medicines can make combinations unsafe.
• Severe weakness, fainting or an irregular heartbeat needs urgent assessment.

Listings are for comparison only. Suitability and supply depend on clinician and pharmacy checks, stock, destination rules and prescription requirements.

What Spironolactone is used for

It may be used for heart failure, hypertension, oedema or hyperaldosteronism. It also has selected anti-androgen uses under clinical care.

How it works

Spironolactone blocks mineralocorticoid receptors in the kidney and other tissues, reducing aldosterone-driven sodium retention and potassium loss.

Important safety checks

Kidney function, potassium, dehydration, pregnancy and interacting medicines require review. ACE inhibitors, ARBs, potassium products, trimethoprim and anti-inflammatory painkillers can increase risk. Breast or sexual changes can occur and should be discussed.

When to seek urgent care

Seek urgent help for severe muscle weakness, fainting, confusion, a slow or irregular heartbeat, very low urine output, facial swelling or breathing difficulty.

Further reading

• Spironolactone: MedlinePlus Drug Information
• Spironolactone - NHS
• Heart failure - causes, symptoms and treatment - BHF