Eplerenone 💊
Always check the BNF link here for up-to-date prescribing guidance.
- Eplerenone is a selective aldosterone receptor antagonist used in heart failure management.
- It has similar actions to spironolactone but fewer anti-androgenic side effects (e.g. gynaecomastia).
⚙️ Mode of Action
- Competitively binds to aldosterone receptors in the distal nephron.
- Reduces sodium and water retention, lowers preload/afterload, and prevents myocardial remodelling.
📌 Indications
- Licensed: Adjunct in chronic heart failure, especially post-MI with LV dysfunction or CCF Class III–IV.
- Off-label: Sometimes used in resistant hypertension (consult specialist guidance).
💊 Dose
- Start: 25 mg OD. Titrate up to 50 mg OD depending on potassium & renal function.
- Monitor U&E at baseline, 1 week, and 1 month, then regularly.
⚠️ Interactions
- 🚨 Avoid co-administration with other potassium-sparing drugs → risk of severe hyperkalaemia.
- Drugs increasing K⁺: Trimethoprim, Ciclosporin, Tacrolimus.
- Antiarrhythmics: Amiodarone, Diltiazem, Verapamil.
- Antimicrobials (CYP3A4 inhibitors): Ketoconazole, Itraconazole, Clarithromycin, Erythromycin, Ritonavir.
- Other: Digoxin (↑ toxicity), Lithium, Rifampicin, Carbamazepine, Phenytoin.
⛔ Contraindications & Cautions
- Severe renal impairment (eGFR <30 mL/min/1.73m²).
- Baseline serum potassium >5.0 mmol/L.
- Concomitant use with potassium supplements or strong CYP3A4 inhibitors.
- Caution in pregnancy & breastfeeding.
💥 Side Effects
- Hyperkalaemia ⚡ – most serious (requires monitoring).
- Dizziness & hypotension. GI upset: diarrhoea, nausea. Skin rash (rare).
💡 Clinical Pearls
- Eplerenone is preferred over spironolactone if patients develop gynaecomastia.
- Always check renal function & potassium before starting and during therapy.
- Improves survival in patients post-MI with LV systolic dysfunction when added to ACEi + beta-blocker.
