Inspra (Eplerenone) – Oral

What Is Inspra?

Inspra (eplerenone) is an oral prescription medication used to treat heart failure and high blood pressure.

Inspra belongs to a group of drugs called aldosterone antagonists. These medications work by blocking aldosterone—a naturally occurring chemical in your body that causes fluid retention and increases blood pressure. Inspra is also considered a potassium-sparing diuretic since it removes excess fluid from your body without depleting potassium.

What Is Inspra Used For?

The Food and Drug Administration (FDA) approved Inspra to treat heart failure in people who have had a heart attack.

Heart failure describes a condition in which your heart cannot pump enough blood to meet your body's needs. Heart failure sometimes develops after a heart attack due to damage to the heart muscles. Studies have shown that Inspra decreases the risk of dying when used for this purpose.

The FDA also approved Inspra to control high blood pressure (hypertension), particularly when other treatments have failed.

How to Take Inspra

Inspra should be taken at the same time each day—once or twice daily, depending on your condition. Avoid grapefruit and grapefruit juice since grapefruit can raise Inspra levels and increase your risk of side effects. Also, be aware that potassium-containing salt substitutes can cause your potassium levels to become too high with Inspra.

Storage

Store Inspra at controlled room temperature (around 77 degrees Fahrenheit). Short trips out of the house in temperatures ranging from 59 to 86 degrees are permitted. Keep Inspra in a safe location that is high up and out of the reach of children and pets.

Off-Label Uses

Healthcare providers can prescribe medications off-label, meaning for conditions not approved by the FDA. Inspra is sometimes used off-label to treat heart failure in people who have not had a heart attack and for primary aldosteronism—a condition that occurs when your body produces too much aldosterone and causes high blood pressure.

What Are the Side Effects of Inspra?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a medical professional. You may report side effects to the FDA at www.fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Inspra is a well-tolerated medication, and most people don’t experience any side effects. The most common side effect of Inspra is an increase in potassium levels (hyperkalemia). Your healthcare provider will monitor your potassium levels before and during treatment with a blood test to ensure they don’t become too high.

Less common side effects include excess cholesterol and triglycerides in the blood.

Severe Side Effects

Rarely, Inspra may cause serious side effects. Call your healthcare provider right away if you develop any serious reactions. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

High Potassium Levels (Hyperkalemia)

Most people taking Inspra will only develop mild increases in their potassium levels. Rarely, Inspra may cause your potassium levels to become dangerously high. High potassium levels can lead to serious heart rhythm problems and be life-threatening. Call your healthcare provider right away if you experience any symptoms of high potassium, including:

• Stomach pain, vomiting, or diarrhea 
• Chest pain 
• Confusion 
• Feeling weak, lightheaded, or dizzy 
• Irregular heartbeat 
• Muscle weakness 
• Numbness or tingling sensation 
• Trouble breathing

Allergic Reaction

Some people may develop an allergic reaction to Inspra, which can be serious. Watch out for any signs of a reaction, including:

• Hives 
• Itching 
• Rash 
• Red, swollen, blistered, or peeling skin 
• Swelling of the mouth, face, lips, tongue, or throat 
• Tightness in the chest or throat 
• Trouble breathing, swallowing, or talking 
• Wheezing or unusual hoarseness

Dosage: How Much Inspra Should I Take?

Modifications

Healthcare providers generally do not recommend taking Inspra if you are pregnant or breastfeeding. Let your provider know if you’re pregnant or plan to become pregnant before starting Inspra.

Missed Dose

If you miss a dose of Inspra, take it as soon as you remember. If it’s almost time for your next dose, skip the missed dose and resume your regular dosing schedule. Don’t double up or take extra Inspra.

Overdose: What Happens If I Take Too Much Inspra?

While no cases of overdoses have been reported, taking too much Inspra would likely cause low blood pressure and increased potassium levels. Signs of an overdose may include:

• Blurred vision 
• Cold, gray skin 
• Confusion 
• Dizziness 
• Fainting 
• Irregular or slow heartbeat 
• Lack of energy 
• Muscle weakness 
• Tingling in the arms and legs
• Upset stomach

Precautions

What Are Reasons I Shouldn’t Take Inspra?

Certain conditions increase your risk of developing complications from Inspra. Your healthcare provider may treat you with a different medication if any of the following apply to you:

• You have diabetes with protein in your urine.
• You have high blood potassium levels.
• You have severe kidney problems. 
• You take certain medications that increase Inspra levels or increase potassium levels, such as Nizoral (ketoconazole), Sporanox (itraconazole), Serzone (nefazodone), Biaxin (clarithromycin), Kaletra (ritonavir), Viracept (nelfinavir), and potassium pills. 

What Other Medications Interact With Inspra?

Many drugs may interact with Inspra and cause adverse effects. Always keep an updated list of all the medicines you take and share this information with your healthcare providers and pharmacist any time there are changes.

Some medications can increase Inspra levels and should not be taken together. They include:

• Biaxin or Biaxin XL (clarithromycin)
  
• Crixivan (indinavir)
• Invirase (saquinavir)
• Lopinavir
  
• Nizoral (ketoconazole)
• Norvir (ritonavir)
  
• Noxafil (posaconazole)
  
• Onmel and Sporanox (itraconazole)
  
• Prezista (darunavir)
• Reyataz (atazanavir)
• Serzone (nefazodone)
• Tybost (cobicistat)
• Vfend (voriconazole)
• Viekira XR (ombitasvir, paritaprevir, ritonavir, dasabuvir) 
• Viracept (nelfinavir)
  

Other medications can also increase Inspra levels. Your healthcare provider may recommend a lower dose of Inspra if you take any of the following:

• Cardizem (diltiazem)
  
• Erythromycin 
• Diflucan (fluconazole)
• Lexiva (fosamprenavir)
• Multaq (dronedarone)
• Verelan or Calan (verapamil)

Several drugs can increase the risk of developing high potassium levels with Inspra. Some of these medications are commonly taken with Inspra, such as angiotensin-converting enzyme (ACE) inhibitors. Your healthcare provider will closely monitor your potassium levels. Other medications, such as Gengraf (cyclosporine), should also be avoided.

Be cautious when taking the following medications with Inspra:

• ACE inhibitors, such as Qbrelis (lisinopril), Vasotec (enalapril), and Lotensin (benazepril)
• Aldactone (spironolactone)
  
• Angiotensin receptor blockers (ARBs) like Entresto (valsartan), Benicar (olmesartan), or Cozaar (losartan)
• Bactrim (sulfamethoxazole/trimethoprim) 
• Dyazide (triamterene)
  
• Gengraf (cyclosporine) 
  
• Macrobid (nitrofurantoin) 
• Midamor (amiloride)
• Nonsteroidal anti-inflammatory drugs (NSAIDs) like Advil or Motrin (ibuprofen) or Aleve (naproxen) 
• Potassium supplements 
  
• Primsol (trimethoprim)

This is not a complete list of all the medications that may interact with Inspra. Always talk to your healthcare provider or pharmacist before starting anything new.

What Medications Are Similar?

Aldactone (spironolactone) is another potassium-sparing diuretic that blocks aldosterone. It is also used to treat heart failure and high blood pressure. When choosing between Aldactone and Inspra, most healthcare providers will prescribe Aldactone first since it’s less expensive. But some people aren’t able to tolerate Aldactone.

Unlike Inspra, Aldactone causes several unpleasant side effects, including gynecomastia (enlarged breast tissue in men) and sexual dysfunction. Inspra is often prescribed for people who are unable or unwilling to take Aldactone due to its side effects.

How Can I Stay Healthy While Taking Inspra?

Having a condition that affects your heart can be scary—especially if you’ve had a heart attack. Luckily, exercise, diet changes, and medications can all help improve your outcomes. Your healthcare provider may prescribe Inspra as one part of your treatment plan.

Most people tolerate Inspra without any issues, but be sure to regularly follow up with any blood tests your doctor has ordered to ensure you can continue using Inspra safely. Don’t hesitate to let your healthcare team know about all your concerns. Together you will develop a plan that keeps you and your heart healthy.