Drug Guide
Eplerenone
Classification
Therapeutic: Antihypertensive, Diuretic
Pharmacological: Mineralocorticoid receptor antagonist
FDA Approved Indications
- Hypertension
- Heart failure post myocardial infarction with left ventricular systolic dysfunction
Mechanism of Action
Eplerenone selectively blocks mineralocorticoid receptors, reducing sodium retention and potassium excretion, leading to decreased blood pressure and fluid retention.
Dosage and Administration
Adult: Initially 25 mg once daily; can be increased to 50 mg once daily based on response and serum potassium levels.
Pediatric: Not typically used in pediatric patients; safety and efficacy not established.
Geriatric: Start at lower end of dosing range; monitor closely.
Renal Impairment: Reduce dose in patients with serum creatinine >2.0 mg/dL or eGFR <50 mL/min/1.73 m².
Hepatic Impairment: No specific adjustment; use with caution.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Extensively bound to plasma proteins.
Metabolism: Primarily metabolized by CYP3A4.
Excretion: Excreted in urine and feces.
Half Life: Approximately 4-6 hours.
Contraindications
- Type 2 diabetes and elevated fasting serum glucose levels (due to risk of hyperkalemia)
Precautions
- Hyperkalemia, renal impairment, concomitant use of strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin).
Adverse Reactions - Common
- Hyperkalemia (Common)
- Dizziness (Common)
- Hypotension (Common)
Adverse Reactions - Serious
- Serious hyperkalemia leading to arrhythmias (Uncommon)
- Renal impairment worsening (Uncommon)
Drug-Drug Interactions
- Potassium-sparing diuretics, ACE inhibitors, NSAIDs, CYP3A4 inhibitors like ketoconazole, clarithromycin.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor blood pressure, serum potassium, renal function.
Diagnoses:
- Risk for hyperkalemia
- Risk for decreased cardiac output
Implementation: Administer with food to enhance absorption; monitor labs regularly.
Evaluation: Assess blood pressure response and serum potassium levels periodically.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Avoid potassium-containing salt substitutes.
- Report muscle weakness, fatigue, or irregular heartbeat.
- Stay hydrated and avoid excessive potassium intake.
Special Considerations
Black Box Warnings:
- Hyperkalemia risk, especially in patients with renal impairment or on other potassium-sparing drugs.
Genetic Factors: Consider pharmacogenomics for CYP3A4 metabolism affecting drug levels.
Lab Test Interference: May affect serum potassium and renal function tests.
Overdose Management
Signs/Symptoms: Hyperkalemia, hypotension.
Treatment: Discontinue medication, monitor electrolytes, supportive care, and manage hyperkalemia per protocols.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F).
Stability: Stable up to the expiration date when stored properly.