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Quick facts
- Drug class
- Aldosterone Antagonist [EPC], Aldosterone Antagonists [MoA]
- How it is given
- oral
- Type
- human prescription drug
- Brand names
- Inspra
- RxNorm ID
- 351256
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
is an aldosterone antagonist indicated for: • Improving survival of stable adult patients with symptomatic heart failure with reduced ejection fraction (HFrEF) after an acute myocardial infarction. ( 1.1 ) • The treatment of hypertension in adults, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. ( 1.2 ) 1.1 Heart Failure Post-Myocardial Infarction INSPRA is indicated to improve survival of stable adult patients with symptomatic heart failure with reduced ejection fraction (≤40%) (HFrEF) after an acute myocardial infarction (MI). 1.2 Hypertension INSPRA is indicated for the treatment of hypertension in adults, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular (CV) events, primarily strokes and MI. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes. Control of high blood pressure should be part of comprehensive CV risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program’s Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce CV morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent CV outcome benefit has been a reduction in the risk of stroke, but reductions in MI and CV mortality also have been seen regularly. […]
About this medicine
contains eplerenone, a blocker of aldosterone binding at the mineralocorticoid receptor. Eplerenone is chemically described as Pregn-4-ene-7,21-dicarboxylic acid, 9,11-epoxy-17-hydroxy-3-oxo-, γ-lactone, methyl ester, (7α,11α,17α)-. Its empirical formula is C 24 H 30 O 6 and it has a molecular weight of 414.50. The structural formula of eplerenone is represented below: Eplerenone is an odorless, white to off-white crystalline powder. It is very slightly soluble in water, with its solubility essentially pH-independent. The octanol/water partition coefficient of eplerenone is approximately 7.1 at pH 7.0. INSPRA tablets for oral administration contain 25 mg or 50 mg of eplerenone and the following inactive ingredients: croscarmellose sodium, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, red iron oxide, sodium lauryl sulfate, talc, titanium dioxide, and yellow iron oxide. structural formula of eplerenone
How it works
12.1 Mechanism of Action Eplerenone binds to the mineralocorticoid receptor and blocks the binding of aldosterone, a component of the renin-angiotensin-aldosterone-system (RAAS). Aldosterone synthesis, which occurs primarily in the adrenal gland, is modulated by multiple factors, including angiotensin II and non-RAAS mediators such as adrenocorticotropic hormone (ACTH) and potassium. Aldosterone binds to mineralocorticoid receptors in both epithelial (e.g., kidney) and nonepithelial (e.g., heart, blood vessels, and brain) tissues and increases blood pressure through induction of sodium reabsorption and possibly other mechanisms. Eplerenone has been shown to produce sustained increases in plasma renin and serum aldosterone, consistent with inhibition of the negative regulatory feedback of aldosterone on renin secretion. The resulting increased plasma renin activity and aldosterone circulating levels do not overcome the effects of eplerenone. Eplerenone selectively binds to human mineralocorticoid receptors relative to its binding to recombinant human glucocorticoid, progesterone, and androgen receptors.
Who should not take it
For All Patients INSPRA is contraindicated in all patients with: • serum potassium >5.5 mEq/L at initiation, • creatinine clearance ≤30 mL/min, or • concomitant administration of strong CYP3A inhibitors (e.g., ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, and nelfinavir) [see Drug Interactions (7.1) , Clinical Pharmacology (12.3) ] . For Patients Treated for Hypertension INSPRA is contraindicated for the treatment of hypertension in patients with: • type 2 diabetes with microalbuminuria, • serum creatinine >2.0 mg/dL in males or >1.8 mg/dL in females, • creatinine clearance <50 mL/min, or • concomitant administration of potassium supplements or potassium-sparing diuretics (e.g., amiloride, spironolactone, or triamterene) [see Warnings and Precautions (5.1) , Adverse Reactions (6.2) , Drug Interactions (7) , and Clinical Pharmacology (12.3) ] . For all patients: • Serum potassium >5.5 mEq/L at initiation ( 4 ) • Creatinine clearance ≤30 mL/min ( 4 ) • Concomitant use with strong CYP3A inhibitors ( 4 , 7.1 ) For the treatment of hypertension: • Type 2 diabetes with microalbuminuria ( 4 ) • Serum creatinine >2.0 mg/dL in males, >1.8 mg/dL in females ( 4 ) • Creatinine clearance <50 mL/min ( 4 ) • Concomitant use of potassium supplements or potassium-sparing diuretics ( 4 )
Warnings and cautions
• Hyperkalemia: Patients with decreased renal function, diabetes, proteinuria or patients who are taking ACEs and ARBs, NSAIDs or moderate CYP3A inhibitors are at increased risk. Monitor serum potassium levels and adjust dose as needed. ( 5.1 ) 5.1 Hyperkalemia The risk of hyperkalemia is higher in patients with impaired renal function, proteinuria, diabetes and those concomitantly treated with ACEs, ARBs, NSAIDs and moderate CYP3A inhibitors. Minimize the risk of hyperkalemia with proper patient selection and monitoring [see Dosage and Administration (2.1) , Contraindications (4) , Adverse Reactions (6.2) , and Drug Interactions (7) ] . Monitor patients for the development of hyperkalemia until the effect of INSPRA is established. Patients who develop hyperkalemia (5.5-5.9 mEq/L) may continue INSPRA therapy with proper dose adjustment. Dose reduction decreases potassium levels. Patients on moderate CYP3A inhibitors that cannot be avoided should have their dose of eplerenone reduced [see Drug Interactions (7.2) ] .
Reported side effects
The following adverse reactions are discussed in greater detail in other sections of the labeling: • Hyperkalemia [see Warnings and Precautions (5.1) ] HFrEF Post-MI: Most common adverse reactions (>2% and more frequent than with placebo): hyperkalemia and increased creatinine. ( 6.1 ) Hypertension: In clinical studies, adverse reactions with INSPRA were uncommon. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Viatris at 1-877-446-3679 (1-877-4-INFO-RX) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in clinical trials of another drug and may not reflect the rates observed in practice. Heart Failure Post-Myocardial Infarction In EPHESUS, safety was evaluated in 3307 patients treated with INSPRA and 3301 placebo-treated patients. The overall incidence of adverse events reported with INSPRA (78.9%) was similar to placebo (79.5%). Adverse events occurred at a similar rate regardless of age, gender, or race. Patients discontinued treatment due to an adverse event at similar rates in either treatment group (4.4% INSPRA vs. 4.3% placebo), with the most common reasons for discontinuation being hyperkalemia, MI, and abnormal renal function. Adverse reactions that occurred more frequently in patients treated with INSPRA than placebo were hyperkalemia (3.4% vs. 2.0%) and increased creatinine (2.4% vs. 1.5%). Discontinuations due to hyperkalemia or abnormal renal function were less than 1.0% in both groups. Hypertension INSPRA has been evaluated for safety in 3091 patients treated for hypertension. A total of 690 patients were treated for over 6 months and 106 patients were treated for over 1 year. In placebo-controlled studies, the overall rates of adverse events were 47% with INSPRA and 45% with placebo. Adverse events occurred at a similar rate regardless of age, gender, or race. Therapy was discontinued due to an adverse event in 3% of patients treated with INSPRA and 3% of patients given placebo. […]
Interactions with other medicines
• CYP3A Inhibitors: In post-MI HFrEF patients, do not exceed 25 mg once daily when used with moderate CYP3A inhibitors (e.g., verapamil, erythromycin, saquinavir, fluconazole). In patients with hypertension, initiate at 25 mg once daily. For inadequate blood pressure response, dosing may be increased to a maximum of 25 mg twice daily. ( 2.4 , 7.1 , 12.3 ) 7.1 CYP3A Inhibitors Eplerenone metabolism is predominantly mediated via CYP3A. Do not use INSPRA with drugs that are strong inhibitors of CYP3A [see Contraindications (4) and Clinical Pharmacology (12.3) ] . In post-MI HFrEF patients taking a moderate CYP3A inhibitor, do not exceed 25 mg once daily. In patients with hypertension taking a moderate CYP3A inhibitor, initiate at 25 mg once daily. For inadequate blood pressure response, dosing may be increased to a maximum of 25 mg twice daily [see Dosage and Administration (2.3 , 2.4) and Clinical Pharmacology (12.3) ] . 7.2 ACE Inhibitors and Angiotensin II Receptor Antagonists The risk of hyperkalemia increases when eplerenone is used in combination with an ACE inhibitor and/or an ARB. A close monitoring of serum potassium and renal function is recommended, especially in patients at risk for impaired renal function, e.g., the elderly [see Warnings and Precautions (5.1) ] . 7.3 Lithium A drug interaction study of eplerenone with lithium has not been conducted. Lithium toxicity has been reported in patients receiving lithium concomitantly with diuretics and ACE inhibitors. Serum lithium levels should be monitored frequently if INSPRA is administered concomitantly with lithium. 7.4 Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) A drug interaction study of eplerenone with an NSAID has not been conducted. The administration of other potassium-sparing antihypertensives with NSAIDs has been shown to reduce the antihypertensive effect in some patients and result in severe hyperkalemia in patients with impaired renal function. Therefore, when INSPRA and NSAIDs are used concomitantly, monitor blood pressure and serum potassium levels.
Use in specific groups
8.1 Pregnancy Risk Summary The available data from published case reports on eplerenone use during pregnancy are insufficient to establish a drug-associated risk of major birth defects, miscarriage, adverse maternal or fetal outcomes (see Clinical Considerations ) . In animal studies, no adverse developmental effects were observed when eplerenone was administered to pregnant rats and rabbits during organogenesis at exposures 32 and 31 times, respectively the human exposure at the 100 mg/day therapeutic dose. The estimated background risk of major birth defects and miscarriage for the indicated population are unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Hypertension in pregnancy increases the maternal risk for pre-eclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section, and post-partum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death. Pregnant women with hypertension should be carefully monitored and managed accordingly. Pregnant women with heart failure are at increased risk for preterm birth. Stroke volume and heart rate increase during pregnancy, increasing cardiac output, especially during the first trimester. Clinical classification of heart disease may worsen with pregnancy and lead to maternal death. Closely monitor pregnant patients for destabilization of their heart failure. Data Animal Data Embryo-fetal development studies were conducted with doses up to 1000 mg/kg/day in rats and 300 mg/kg/day in rabbits (exposures up to 32 and 31 times the human AUC for the 100 mg/day therapeutic dose, respectively) administered during organogenesis. No teratogenic effects were seen in rats or rabbits, although decreased rat fetal weights were observed, and decreased body weight in maternal rabbits and increased rabbit fetal resorptions and post-implantation loss were observed at the highest administered dosages. […]
If too much is taken
No cases of human overdosage with eplerenone have been reported. Lethality was not observed in mice, rats, or dogs after single oral doses that provided C max exposures at least 25 times higher than in humans receiving eplerenone 100 mg/day. Dogs showed emesis, salivation, and tremors at a C max 41 times the human therapeutic C max , progressing to sedation and convulsions at higher exposures. The most likely manifestation of human overdosage would be anticipated to be hypotension or hyperkalemia. Eplerenone cannot be removed by hemodialysis. Eplerenone has been shown to bind extensively to charcoal. If symptomatic hypotension should occur, supportive treatment should be instituted. If hyperkalemia develops, standard treatment should be initiated.
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This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 23 June 2025. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.