Eplerenone (Inspra) is a selective aldosterone receptor antagonist, primarily indicated for improving survival in patients with heart failure following acute myocardial infarction and treating hypertension in adults.

What are the precautions for using Eplerenone (Inspra)?

Contraindication Screening

(1) Initial serum potassium level > 5.5 mEq/L.

(2) Creatinine clearance ≤ 30 mL/min.

(3) Concomitant use with strong CYP3A inhibitors.

(4) For hypertensive patients, additional contraindications include: type 2 diabetes mellitus with microalbuminuria; serum creatinine > 2.0 mg/dL in males or > 1.8 mg/dL in females; creatinine clearance < 50 mL/min; concurrent use of potassium supplements or potassium-sparing diuretics.

Patient Risk Stratification

Patients with renal impairment, diabetes, proteinuria, as well as those concurrently taking ACE inhibitors, ARBs, NSAIDs, or moderate CYP3A inhibitors have a significantly increased risk of hyperkalemia and require special attention.

Hyperkalemia Risk Management

(1) Risk assessment factors: The risk of hyperkalemia is significantly elevated in patients with renal impairment, diabetes, or proteinuria. The risk is further increased when used in combination with ACE inhibitors, ARBs, NSAIDs, and moderate CYP3A inhibitors.

(2) Monitoring time points: Serum potassium should be measured before initiating eplerenone treatment, within the first week of treatment, and one month after treatment initiation or dose adjustment. Regular assessments are required thereafter.

CYP3A Inhibitors

(1) Eplerenone is mainly metabolized via CYP3A4.

(2) Concomitant use with strong CYP3A inhibitors is prohibited.

(3) For patients with post-myocardial infarction heart failure using moderate CYP3A inhibitors, the dose of eplerenone should not exceed 25 mg once daily.

Precautions for Concomitant Medication Use

(1) The risk of hyperkalemia increases when used in combination with ACE inhibitors and/or ARBs.

(2) Close monitoring of serum potassium and renal function is recommended, especially for patients at risk of renal impairment, such as the elderly.

Medication Monitoring for Eplerenone (Inspra)

Frequency of Serum Potassium Monitoring

Serum potassium levels must be measured before treatment initiation, within the first week of treatment, and one month after treatment initiation or dose adjustment, with regular assessments to follow.

Renal Function Monitoring

When patients start taking moderate-intensity CYP3A inhibitors, ACE inhibitors, angiotensin II receptor blockers, or non-steroidal anti-inflammatory drugs (NSAIDs), serum potassium and serum creatinine should be checked within 3–7 days.