Epleron

Indications

Eplerenone is used together with standard treatment to reduce the risk of death and hospital admission in adults with heart failure with reduced pumping strength (low ejection fraction), including people who develop heart failure after a heart attack. It is also used in some countries to treat high blood pressure.

How It Works

Eplerenone blocks the action of aldosterone, a hormone that makes the body keep salt and water and lose potassium. Too much aldosterone also causes scarring and stiffening of the heart and blood vessels. By blocking it, Eplerenone helps the body pass out extra salt and water, lowers blood pressure, and protects the heart from further damage. It is more selective than Spironolactone, so it causes fewer hormonal side effects such as breast enlargement.

Dosage and Administration

• Heart failure (adults): usually started at 25 mg once daily and increased to 50 mg once daily within about 4 weeks, depending on blood potassium levels, as prescribed.
• High blood pressure (adults): usually 50 mg once daily, as prescribed.

Take at the same time each day, with or without food. Your doctor will check blood potassium and kidney function before starting, after one week, after one month and regularly afterwards.

Interactions

• Strong CYP3A4 blockers such as Ketoconazole, Itraconazole, Clarithromycin, Ritonavir and Nelfinavir: must not be taken with Eplerenone.
• Moderate CYP3A4 blockers such as Erythromycin, Verapamil and Fluconazole: a lower dose is needed.
• Potassium supplements, salt substitutes containing potassium, potassium-sparing diuretics (Amiloride, Spironolactone, Triamterene), ACE inhibitors, ARBs and Trimethoprim: increased risk of high potassium.
• NSAIDs such as Ibuprofen: may reduce kidney function and raise potassium.
• Lithium: levels may rise.
• St John's Wort, Rifampicin, Carbamazepine and Phenytoin: may reduce its effect.

Contraindications

• Blood potassium above 5.0 mmol/L at the start of treatment.
• Severe kidney impairment.
• Severe liver impairment.
• Use of strong CYP3A4 blockers or of potassium-sparing diuretics and potassium supplements.
• Allergy to Eplerenone.

Side Effects

Common effects include high blood potassium, dizziness, low blood pressure (especially when standing up), diarrhoea, nausea, cough and changes in kidney function tests. Less common effects include rash, muscle cramps and, rarely, breast enlargement.

Get urgent medical help if you have muscle weakness, a slow or irregular heartbeat, fainting, very little urine, or swelling of the face, lips or throat.

Pregnancy and Lactation

There is limited information in pregnancy: use only if the doctor considers it clearly needed. It is not known whether it passes into human breast milk; a decision whether to breastfeed or take the medicine should be made with your doctor.

Precautions and Warnings

• Regular blood tests for potassium and kidney function are essential.
• Avoid high-potassium salt substitutes unless your doctor approves.
• If you have vomiting, diarrhoea or are unable to drink, contact your doctor: the dose may need to be paused.
• Elderly people and those with diabetes or kidney problems are at higher risk of high potassium.
• It may cause dizziness: take care when driving.

Overdose

Overdose may cause low blood pressure and high blood potassium. Seek emergency medical help.

Therapeutic Class

Mineralocorticoid (aldosterone) receptor antagonist; potassium-sparing diuretic.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.