Cardiology · Aldosterone antagonist (MRA)
Spironolactone
Dose
12.5–50 mg PO OD (HF); 100–400 mg/day (ascites)
Mechanism
Competitive aldosterone antagonist → K-sparing diuresis; antiandrogen
Indications
- • HFrEF (4th pillar)
- • Resistant hypertension
- • Primary hyperaldosteronism
- • Cirrhotic ascites
Contraindications
- • K⁺ >5.0
- • eGFR <30 (relative)
- • Addison disease
Use
Prognostic in HFrEF; check K⁺ and creatinine at 1, 4, 12 weeks.
Monitoring
K⁺, creatinine, BP.
Side effects
- • Hyperkalaemia
- • Gynaecomastia
- • Menstrual irregularity
- • AKI
Always confirm dose against your local formulary / BNF before prescribing.
