Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Inspra (Eplerenone). If you are concerned about side effects, discuss the risks and benefits of Inspra (Eplerenone) with your doctor.

The following side effects have been reported by at least 1% of people taking Inspra (Eplerenone). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• dehydration (i.e., Headaches, dizziness, or fainting)
• dizziness when getting up from a sitting or lying position (Low Blood Pressure)
• headache
• heartburn
• indigestion

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• Angina or chest pain
• difficulty breathing
• fainting
• increased levels of potassium in the blood (e.g., irregular heartbeat, slowed heart rate, nausea)
• shortness of breath or difficulty breathing
• signs of a blood clot in blood vessels, such as sudden vision change or dizziness, chest pain, pain and swelling in the leg muscle
• signs of heart rhythm changes (e.g., dizziness, fainting, rapid heartbeat, pounding heartbeat)
• signs of liver problems (e.g., nausea, vomiting, Diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, Fever, chills, rapid heartbeat, swollen abdomen)
• signs of urinary tract infection (e.g., painful or difficult urination or a decrease in the amount of urine)
• symptoms of Hypothyroidism - underactive Thyroid gland (e.g., dry skin, Constipation, weight gain, fatigue, aches, pains and stiffness, intolerance to cold, Depression, memory problems)
• trouble swallowing
• weight gain

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a heart attack (e.g., chest pain, shoulder pain, difficulty breathing, dizziness)
• signs of heart failure (e.g., fast or irregular heartbeat; swelling of lower legs, feet, and abdomen; wheezing; trouble breathing; or shortness of breath)
• symptoms of an allergic reaction (e.g., swelling of the hands, feet, ankles, face, lips, mouth, or throat; difficulty breathing or swallowing)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Inspra (Eplerenone).

25 mg
Each yellow, diamond, biconvex, film-coated tablet, debossed "Pfizer" on one side and "NSR" over "25" on the other, contains Inspra (Eplerenone) 25 mg. Nonmedicinal ingredients: croscarmellose sodium, hypromellose, lactose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, sodium lauryl sulfate, talc, titanium dioxide, iron oxide yellow, and iron oxide red.

50 mg
Each yellow, diamond, biconvex, film-coated tablet, debossed "Pfizer" on one side and "NSR" over "50" on the other, contains Inspra (Eplerenone) 50 mg. Nonmedicinal ingredients: croscarmellose sodium, hypromellose, lactose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, sodium lauryl sulfate, talc, titanium dioxide, iron oxide yellow, and iron oxide red.

Do not take Inspra (Eplerenone) if you:

• are allergic to Inspra (Eplerenone) or any ingredients of the medication
• are taking other medications that may affect how the body gets rid of Inspra (Eplerenone) (e.g., ketoconazole, itraconazole, nefazodone, telithromycin, clarithromycin, ritonavir, nelfinavir)
• are taking potassium supplements or potassium-sparing diuretics (e.g., Spironolactone)
• have high levels of potassium in your blood
• have severe kidney dysfunction
• have severe liver dysfunction

In addition, if you are taking Inspra (Eplerenone) for high blood pressure, do not take Inspra (Eplerenone) if you:

• have Type 2 Diabetes with protein in the urine
• have moderate-to-severe kidney dysfunction
• have high levels of creatinine in your blood

There may be an interaction between Inspra (Eplerenone) and any of the following:

• Abiraterone
• Aldesleukin
• Aliskiren
• alpha-agonists (e.g., Clonidine, methyldopa)
• alpha-blockers (e.g., Alfuzosin, Doxazosin, Tamsulosin)
• amifostine
• Amiodarone
• amphetamines (e.g., Dextroamphetamine, Lisdexamfetamine)
• angiotensin converting enzyme inhibitors (ACEIs; e.g., Captopril, Lisinopril, Ramipril)
• angiotensin receptor blockers (ARBs; e.g., Candesartan, Irbesartan, Losartan)
• anti-psychotics (e.g., Clozapine, Olanzapine, Quetiapine, Risperidone)
• Apalutamide
• Aprepitant
• "azole" antifungals (e.g., itraconazole, ketoconazole, Voriconazole)
• barbiturates (e.g., butalbital, Phenobarbital)
• beta-adrenergic blockers (e.g., Atenolol, Propranolol, Sotalol)
• Bicalutamide
• Bosentan
• brimonidine
• calcium channel blockers (e.g., Diltiazem, Verapamil)
• Carbamazepine
• conivaptan
• Cyclosporine
• Deferasirox
• Desipramine
• dexmethylphenidate
• Digoxin
• diuretics (water pills; e.g., Furosemide, Hydrochlorothiazide, triamterene)
• Dronedarone
• drospirenone
• Duloxetine
• Enzalutamide
• Guanfacine
• grapefruit juice
• Heparin
• Hepatitis C antivirals (e.g., dasabuvir, ombitasvir, paritaprevir)
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• levodopa
• lithium
• Lomitapide
• low molecular weight heparins (e.g., Dalteparin, Enoxaparin, Tinzaparin)
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• Methylphenidate
• mifepristone
• Mitotane
• Modafinil
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, Phenelzine, Rasagiline, Selegiline, Tranylcypromine)
• narcotic pain relievers (e.g., Codeine, Fentanyl, Morphine, Oxycodone)
• nitrates (e.g., Nitroglycerin, isosorbide dinitrate, isosorbide mononitrate)
• Nitrofurantoin
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g. Diclofenac, Ibuprofen, Ketorolac, Naproxen)
• Obinutuzumab
• Oxcarbazepine
• Pentoxifylline
• Phenytoin
• phosphodiesterase 5 inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil)
• potassium supplements or salt substitutes containing potassium
• primidone
• protein kinase inhibitors (e.g., Crizotinib, Dabrafenib, Dasatinib, imatinib)
• quinidine
• rifabutin
• rifampin
• Rituximab
• St. John's wort
• Sarilumab
• Sertraline
• siltuximab
• sodium phosphates
• Tacrolimus
• Tocilizumab
• Tolvaptan
• Trimethoprim
• Yohimbine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Inspra (Eplerenone). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Inspra (Eplerenone).

Diabetes: People with diabetes that have heart failure after a heart attack, especially those who have proteinuria (protein in the urine), appear to have a higher rate of hyperkalemia (high blood potassium; see below). If you have diabetes, discuss with your doctor how Inspra (Eplerenone) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Inspra (Eplerenone), and whether any special monitoring is needed.

Kidney problems: The safety of Inspra (Eplerenone) when used to treat people with moderate-to-severe kidney dysfunction has not been determined. These people should not take Inspra (Eplerenone).

If you have reduced kidney function or Kidney Disease, discuss with your doctor how Inspra (Eplerenone) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Inspra (Eplerenone), and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Inspra (Eplerenone) to build up in the body, causing side effects.

If you have liver problems, discuss with your doctor how Inspra (Eplerenone) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Inspra (Eplerenone), and whether any special monitoring is needed.

The safety of Inspra (Eplerenone) when used to treat people with severe liver dysfunction has not been determined. These people should not take Inspra (Eplerenone).

Potassium levels: Too much potassium in the blood (hyperkalemia) is one of the most common risks of Inspra (Eplerenone). Hyperkalemia that is not recognized and treated can cause serious heart rhythm problems, which can sometimes be fatal. Your doctor will monitor your potassium levels before starting Inspra (Eplerenone), during the first week of taking Inspra (Eplerenone), and periodically throughout your therapy.

Do not take potassium supplements (including dietary potassium) or salt substitutes at the same time as Inspra (Eplerenone) unless directed to do so by your doctor. If you experience an irregular, slow, or weak heartbeat, contact your doctor as soon as possible.

Pregnancy: Inspra (Eplerenone) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Inspra (Eplerenone), contact your doctor immediately.

Breast-feeding: It is not known if Inspra (Eplerenone) passes into breast milk. If you are a breast-feeding mother and are taking Inspra (Eplerenone), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Inspra (Eplerenone) have not been established for children. Inspra (Eplerenone) is not recommended for children.

Seniors: People over the age of 65 may be at increased risk of experiencing side effects from this mediation as a result of decreased kidney function. Doses for seniors may start lower and increase more slowly than for other adults.