Eplerenone is a type of drug called an aldosterone inhibitor, which works by blocking aldosterone receptors in the body and changing the way that urine is produced, leading to more urine being excreted. It is often used with other medications if you have heart failure to reduce the risk of complications and the need for hospitalization.
If you or someone you know is taking eplerenone and you’d like to know more about how it works, let’s take a closer look.
Brand Names and Doses
Eplerenone is the generic name – the name of the actual drug component inside your medication. The brand name written on the packaging might be slightly different such as Inspra, which is the name given by the manufacturing company.
There are two different doses of Inspra available: 25 mg and 50mg. Your doctor may recommend that you begin with the lower dose of 25 mg once a day, which can be increased to 50 mg daily after about a month, depending on the response of your body. This helps to decrease the risk of any side effects as your body adjusts to the drug.
What type of drug is it?
Eplerenone is a type of drug called an aldosterone antagonist. This is a drug class that helps us to group drugs that work in a similar way together. Spironolactone is another drug that is an aldosterone inhibitor and works in a similar way to eplerenone.
Although they are similar in their effect, there are a few subtle differences that might make one or the other a better choice for you. Eplerenone is a newer drug that might be more expensive, but it is less likely to cause endocrine side effects (e.g. menstrual abnormalities and sexual dysfunction). However, it can interact with other drugs that you may be taking more often than spironolactone.
What is eplerenone used for?
Eplerenone is most commonly used to reduce the risk of complication and death for people with heart failure. It can also be used to improve outcomes if you have left ventricular impairment shortly after having a heart attack (myocardial infarction).
It has been shown to improve survival and reduce the chance that you will need to go to hospital for emergency medical care if you are affected by one of these conditions.
How does it work?
Eplerenone has two main ways that it can work in your body: it changes the way that your urine is produced and it changes the effect of aldosterone in your body.
Usually, your urine is produced by your kidneys, which filter the blood to remove the waste products and reabsorb the things it needs back into the bloodstream. Eplerenone binds to the aldosterone receptors and stops aldosterone from having its normal effect on the kidneys and urine production. As a result, more sodium and water is excreted (you will need to urinate more often than usual) and more potassium is absorbed back into your body.
Aldosterone itself may also contribute to heart failure and worsen the condition, so blocking its effects with eplerenone may help to improve outcomes.
If you are taking eplerenone, you may notice some side effects such as:
- High potassium concentration (hyperkalemia)
- Increased urination
- Altered renal function
If you notice these signs, you may need to discuss this with your doctor, who will help you to make changes to the dose or medication as needed.
A common effect of taking eplerenone is a higher concentration of potassium than usual, known as hyperkalemia. If you already have high potassium levels, eplerenone should not be used as it is likely to get even higher. Additionally, if you have diabetes or proteinuria, you are more likely to be affected by this and should avoid taking eplerenone.
For the same reason, you should not take any supplements that contain potassium while taking this medication. Foods that contain high amounts of potassium (e.g. dark green leafy vegetables, bananas, squash) should be eaten in moderation.
It is important that you have regular check-ups with your doctor with blood tests to keep an eye on the concentration of potassium in your blood so that the dose can be changed if needed.
Sometimes when you take eplerenone with together other drugs, the way they work can interact and change their effect on your body.
It should not be used with drugs that strongly inhibit the enzyme (CYP3A4) that is needed to break down epleronone in the body, such as ketoconazole or itraconazole. If it is used with these medications, the concentration of eplerenone is likely to rise and may cause side effects.
Additionally, it is not wise to combine it with other drugs that may increase potassium concentration, like ACE inhibitors. This is because the cumulative effect is more likely to cause problems.
It may also interact with:
If you are taking any of these drugs, it is best to make sure that your doctor knows so that they can make the best decision for your health.
Pregnancy and Breastfeeding
There is currently no research to investigate the effect of eplerenone during pregnancy or breastfeeding.
For this reason, it is not usually recommended for pregnancy women or those who are breastfeeding. However, it may be used in some cases if the benefit is thought to be greater than the risks to the mother and child.