Inspra Side Effects Center

Last updated on RxList: 6/14/2021
Inspra Side Effects Center

What Is Inspra?

Inspra (eplerenone) is an aldosterone receptor blocker, which is an antihypertensive, used to treat congestive heart failure after a heart attack, and is also used to treat high blood pressure (hypertension). Inspra is available in generic form.

What Are Side Effects of Inspra?

Common side effects of Inspra include:

  • headache,
  • dizziness,
  • diarrhea,
  • stomach pain,
  • nausea,
  • cough or flu-like symptoms (such as fever, chills, body aches, unusual tiredness),
  • vaginal bleeding, or
  • breast swelling or tenderness.

Tell your doctor if you have rare but serious side effects of Inspra including:

  • abnormal vaginal bleeding,
  • enlarged or sore breasts in males, or
  • symptoms of a high potassium blood level (such as muscle weakness, slow/irregular heartbeat).

Dosage for Inspra

Treatment with Inspra is initiated at 25 mg once daily and adjusted to the recommended dose of 50 mg once daily, preferably within 4 weeks as tolerated by the patient.

What Drugs, Substances, or Supplements Interact with Inspra?

Inspra may interact with lithium, other blood pressure medications, antibiotics, antifungals, ACE inhibitors, NSAIDs (non-steroidal anti-inflammatory drugs), HIV/AIDS medicines, or antidepressants. Tell your doctor all medications you are taking.

Inspra During Pregnancy or Breastfeeding

During pregnancy, Inspra should be used only when prescribed. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our Inspra (eplerenone) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Inspra Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; severe stomach pain; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • a light-headed feeling, like you might pass out;
  • diarrhea, vomiting;
  • little or no urination;
  • fast or irregular heartbeats;
  • trouble breathing;
  • swelling in your feet or lower legs; or
  • high potassium--nausea, weakness, tingly feeling, chest pain, irregular heartbeats, loss of movement.

Common side effects may include:

  • high potassium;
  • headache; or
  • dizziness.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Inspra Professional Information


The following adverse reactions are discussed in greater detail in other sections of the labeling:

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.


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. The most common reasons for discontinuation of INSPRA were headache, dizziness, angina pectoris/MI, and increased GGT.

Gynecomastia and abnormal vaginal bleeding were reported with INSPRA but not with placebo. The rates increased with increasing duration of therapy.

Postmarketing Experience

The following adverse reactions have been identified during postapproval use of INSPRA. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Skin: angioneurotic edema, rash

Clinical Laboratory Test Findings

Heart Failure Post-Myocardial Infarction


Increases of more than 0.5 mg/dL were reported for 6.5% of patients administered INSPRA and for 4.9% of placebo-treated patients.


In EPHESUS [see Clinical Studies], the frequencies of patients with changes in potassium (<3.5 mEq/L or >5.5 mEq/L or ≥6.0 mEq/L) receiving INSPRA compared with placebo are displayed in Table 2.

Table 2: Hypokalemia (<3.5 mEq/L) or Hyperkalemia (>5.5 or ≥6.0 mEq/L) in EPHESUS

Potassium (mEq/L) INSPRA
n (%)
n (%)
<3.5 273 (8.4) 424 (13.1)
>5.5 508 (15.6) 363 (11.2)
≥6.0 180 (5.5) 126 (3.9)

Rates of hyperkalemia increased with decreasing renal function.

Table 3: Rates of Hyperkalemia ( >5.5 mEq/L) in EPHESUS by Baseline Creatinine Clearance*

Baseline Creatinine Clearance INSPRA
n (%)
n (%)
≤30 mL/min 160 (32) 82 (23)
31-50 mL/min 122 (24) 46 (13)
51-70 mL/min 86 (17) 48 (13)
>70 mL/min 56 (11) 32 (9)
* Estimated using the Cockroft-Gault formula.

The rates of hyperkalemia in EPHESUS in the INSPRA treated group vs. placebo were increased in patients with proteinuria (16% vs 11%), diabetes (18% vs. 13%) or both (26% vs. 16%).



In placebo-controlled fixed-dose studies, the mean increases in serum potassium were dose-related and are shown in Table 4 along with the frequencies of values >5.5 mEq/L.

Table 4: Increases in Serum Potassium in the Placebo-Controlled, Fixed-Dose Hypertension Studies of INSPRA

Daily Dosage n Mean Increase mEq/L % >5.5 mEq/L
Placebo 194 0 1
25 97 0.08 0
50 245 0.14 0
100 193 0.09 1

Read the entire FDA prescribing information for Inspra (Eplerenone)

© Inspra Patient Information is supplied by Cerner Multum, Inc. and Inspra Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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