Spironolactone (Ascites / Cirrhosis)

How it works

It competitively blocks the mineralocorticoid receptor in the distal nephron, promoting sodium and water excretion while retaining potassium, directly countering the high aldosterone state of decompensated liver disease.

Prescribing in practice

• Hyperkalaemia is the principal hazard — risk is compounded in cirrhosis by renal impairment and concurrent ACE inhibitors, ARBs or potassium supplements, and can precipitate dangerous arrhythmia.
• It is the preferred initial diuretic in cirrhotic ascites and is often paired with a loop diuretic (e.g. furosemide) when used at higher intensity to maintain a balanced electrolyte effect.
• Aim for gradual fluid loss and watch for over-diuresis, which can precipitate hyponatraemia, hepatic encephalopathy or hepatorenal deterioration.

Monitoring

Monitor serum potassium, sodium, renal function and body weight regularly, particularly after initiation or dose changes.

Counselling the patient

• Report muscle weakness, palpitations or confusion, which may signal electrolyte disturbance.
• Avoid potassium-containing salt substitutes and over-the-counter potassium supplements.
• Men may notice breast tenderness or enlargement (gynaecomastia) with prolonged use.

Evidence & guidelines

Spironolactone-based regimens are endorsed by NICE and EASL guidance as first-line diuretic therapy for cirrhotic ascites.