1. Introduction
Eplerenone is a selective aldosterone receptor antagonist used to treat heart failure and hypertension. By blocking aldosterone, it reduces sodium and water retention while sparing potassium, thereby lowering blood pressure and reducing the workload on the heart. Eplerenone is often used in patients intolerant to spironolactone due to its lower risk of causing hormonal side effects.
2. Indications
- Approved Indications:
- Heart failure with reduced ejection fraction (HFrEF) after myocardial infarction to reduce mortality and hospitalisation.
- Hypertension (as monotherapy or adjunctive therapy).
- Off-Label Uses:
- Primary aldosteronism (when surgery is not possible).
- Resistant hypertension.
3. Dosage
- Adults:
- Heart Failure (Post-MI): Start with 25 mg once daily; titrate to 50 mg once daily within 4 weeks based on tolerance.
- Hypertension: Start with 50 mg once daily; may increase to 50 mg twice daily if necessary.
- Elderly:
- No specific dose adjustment is required, but monitor renal function and potassium closely.
- Renal Impairment:
- CrCl ≥50 mL/min: No dose adjustment required.
- CrCl 30–50 mL/min: Start with 25 mg every other day.
- CrCl <30 mL/min: Contraindicated.
4. Administration
- Take orally with or without food.
- Consistent timing (e.g., morning or evening) is recommended for optimal effect.
5. Forms Available
- Tablets: 25 mg, 50 mg.
6. Side Effects
6.1. Common Side Effects
- Hyperkalaemia (elevated potassium levels).
- Dizziness.
- Fatigue.
6.2. Less Common Side Effects
- Headache.
- Diarrhoea.
- Cough.
6.3. Rare but Serious Side Effects
- Severe hyperkalaemia (can lead to life-threatening arrhythmias).
- Allergic reactions (e.g., rash, itching, swelling).
7. Warnings
- Hyperkalaemia: Monitor potassium levels closely, especially in patients with renal impairment, diabetes, or concurrent use of potassium-sparing diuretics.
- Renal Impairment: Contraindicated in patients with severe renal dysfunction (CrCl <30 mL/min).
- Hepatic Impairment: Use cautiously in patients with moderate liver impairment.
8. Precautions
- Avoid use with strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin) as they can significantly increase eplerenone levels.
- Use cautiously in elderly patients or those with mild renal impairment due to an increased risk of hyperkalaemia.
9. Interactions
- Drug-Drug Interactions:
- ACE inhibitors and ARBs: Increased risk of hyperkalaemia.
- NSAIDs: May reduce the antihypertensive effect and increase the risk of renal dysfunction.
- Potassium supplements: Avoid due to the risk of severe hyperkalaemia.
- CYP3A4 inhibitors (e.g., itraconazole, ritonavir): Increased eplerenone plasma levels.
- Drug-Food Interactions:
- No significant food interactions.
10. Monitoring Parameters
- Serum potassium and renal function before initiation and periodically thereafter.
- Blood pressure and symptoms of hypotension.
- Monitor for signs of hyperkalaemia (e.g., muscle weakness, irregular heartbeat).
11. Use in Children
- Safety and efficacy in paediatric populations have not been established.
12. Use in Pregnancy
- Category B: Animal studies have not shown harm to the foetus, but limited human data is available. Use only if benefits outweigh risks.
13. Use in Elderly
- Safe for use, but monitor renal function and potassium closely, as elderly patients are more prone to hyperkalaemia.
14. Use in Kidney Disease
- Contraindicated in severe renal impairment (CrCl <30 mL/min).
- Use cautiously in mild to moderate renal impairment with dose adjustments as needed.
15. Use in Liver Disease
- Use cautiously in patients with moderate liver impairment due to potential changes in drug metabolism.
16. Patient Counselling Points
- Take eplerenone as prescribed, at the same time each day.
- Avoid potassium supplements, salt substitutes containing potassium, and high-potassium foods.
- Inform your doctor if you experience symptoms of hyperkalaemia (e.g., muscle weakness, confusion, or irregular heartbeat).
- Regular blood tests are necessary to monitor potassium and kidney function.
- Do not stop taking eplerenone without consulting your doctor, even if you feel well.
17. Table of Brand Names, Manufacturers, and Prices
Brand Name | Manufacturer | Price (USD) |
---|---|---|
Inspra | Pfizer | $100–150 (30 tablets, 25 mg) |
Generic Eplerenone | Various | $50–100 (30 tablets, 25 mg) |
18. FAQs (15 Questions)
- What is eplerenone used for?
Eplerenone is used to treat heart failure and high blood pressure. - How does eplerenone work?
It blocks aldosterone receptors, reducing sodium and water retention while sparing potassium. - What are the common side effects of eplerenone?
Common side effects include hyperkalaemia, dizziness, and fatigue. - Can eplerenone cause high potassium levels?
Yes, hyperkalaemia is a common side effect and can be serious. Regular monitoring is essential. - How should eplerenone be taken?
Take it once daily, with or without food, as prescribed by your doctor. - Can eplerenone be used during pregnancy?
It may be used if benefits outweigh risks, as there is limited safety data in pregnancy. - What should I avoid while taking eplerenone?
Avoid potassium supplements, salt substitutes containing potassium, and high-potassium foods. - Can eplerenone interact with other medications?
Yes, it interacts with ACE inhibitors, ARBs, NSAIDs, and CYP3A4 inhibitors. - Is eplerenone safe for elderly patients?
Yes, but monitor potassium and kidney function closely in elderly patients. - Can eplerenone be used in children?
Safety and efficacy have not been established in children. - Does eplerenone cause weight gain?
Weight gain is not a common side effect of eplerenone. - Can I drink alcohol while taking eplerenone?
Moderate alcohol consumption is generally safe but may increase dizziness or hypotension. - How long does eplerenone take to work?
Blood pressure reduction may be seen within 2 weeks, but heart failure benefits may take longer. - What should I do if I miss a dose?
Take it as soon as you remember, but skip it if it’s close to the next dose. Do not double up. - How should eplerenone be stored?
Store at room temperature, away from moisture and heat.