Inspra (Eplerenone)

• Eplerenone is used to manage conditions related to excess aldosterone activity.
• Hypertension: lowers blood pressure by reducing sodium retention and water overload.
• Heart failure: improves survival and reduces hospitalizations in patients with reduced ejection fraction.
• Post‑myocardial infarction heart failure: decreases risk of cardiovascular death and heart‑failure hospitalization after an acute myocardial infarction.

• Eplerenone selectively blocks the mineralocorticoid (aldosterone) receptor in the distal nephron, preventing aldosterone‑mediated transcription of sodium‑channel proteins. This reduces sodium reabsorption and potassium excretion, leading to natriuresis, modest diuresis, and attenuation of myocardial remodeling associated with chronic aldosterone excess.

Adverse reactions may occur with any medication. Monitoring and prompt reporting are recommended.

Common Side Effects

• Hyperkalaemia: elevated serum potassium levels.
• Dizziness or light‑headedness.
• Headache.
• Nausea or abdominal discomfort.
• Fatigue.
• Diarrhoea.

Serious or Rare Side Effects

• Severe hyperkalaemia requiring medical intervention.
• Acute renal impairment or worsening kidney function.
• Angioedema or severe allergic reactions.
• Hepatic dysfunction with elevated liver enzymes.
• Life‑threatening hypotension.
• Cardiac arrhythmias associated with electrolyte disturbances.

• Patients should be evaluated for risk factors and monitored during therapy.
• Monitor serum potassium: check levels before initiation and periodically thereafter.
• Assess renal function: evaluate creatinine and eGFR at baseline and during treatment.
• Avoid in severe renal impairment: contraindicated when eGFR is markedly reduced.
• Use caution in diabetes: increased risk of hyperkalaemia.
• Pregnancy and lactation: safety not established; avoid unless benefit outweighs risk.
• Store at ambient temperature: keep in the original pack, protect from moisture and direct sunlight.

Eplerenone may interact with several medicines, requiring dose adjustment or monitoring.

Major Interactions (Avoid)

• ACE inhibitors or ARBs: combined use can cause significant hyperkalaemia.
• Potassium‑sparing diuretics (e.g., amiloride, triamterene): additive risk of hyperkalaemia.
• Potassium supplements or high‑potassium diet: may precipitate dangerous potassium elevations.

Moderate Interactions (Monitor Closely)

• Digoxin: increased serum digoxin levels may occur.
• NSAIDs: can reduce renal clearance and raise potassium.
• Lithium: concurrent use may increase lithium toxicity.
• Thiazide diuretics: may blunt the potassium‑sparing effect.
• Strong CYP3A4 inhibitors: may raise eplerenone concentrations.