Aldactone%25252525252525252525252525252525252525252520%25252525252525252525252525252525252525252528spironolactone%25252525252525252525252525252525252525252529

# Aldactone (spironolactone) ## Overview Spironolactone is a potassium-sparing diuretic and a competitive aldosterone receptor antagonist. It acts primarily in the distal convoluted tubule and collecting duct, promoting sodium and water excretion while retaining potassium. It also exhibits anti-androgen activity. ## Primary Indications * Heart failure (NYHA Class II-IV, HFrEF) * Edema associated with hepatic cirrhosis or nephrotic syndrome * Primary hyperaldosteronism * Essential hypertension * Off-label: Hirsutism, acne, and androgenetic alopecia (dermatology). ## Adult Dosing * **Heart Failure (HFrEF):** Start 12.5–25 mg once daily; titrate to 50 mg daily as tolerated. * **Edema (Cirrhosis/Nephrotic Syndrome):** 100 mg/day initially, titrated to 200–400 mg/day depending on response. * **Primary Hyperaldosteronism:** 100–400 mg/day for preoperative preparation. * **Hypertension:** 25–100 mg/day in one or two divided doses. ## Pediatric Dosing * **Heart Failure:** 1–3 mg/kg/day divided once or twice daily. * **Edema/Hypertension:** 1–3.3 mg/kg/day or 60 mg/m²/day divided once or twice daily. * *Note: Dosing is highly dependent on institutional protocol and severity of underlying condition.* ## Dose Adjustments * **Renal Impairment:** Avoid if CrCl < 30 mL/min due to high risk of hyperkalemia. * **Hepatic Impairment:** Usually no initial adjustment required; monitor closely for fluid/electrolyte balance. ## Contraindications * Anuria or acute renal insufficiency. * Hyperkalemia (> 5.0–5.5 mEq/L). * Concomitant use of eplerenone or potassium supplements/potassium-sparing diuretics. * Addison’s disease. ## Adverse Effects * **Common:** Hyperkalemia, dizziness, headache. * **Endocrine (due to androgen antagonism):** Gynecomastia, breast tenderness, menstrual irregularities, erectile dysfunction, decreased libido. * **Serious:** Severe arrhythmias (due to hyperkalemia), hyponatremia. ## Key Drug Interactions * **Potassium-sparing agents/supplements:** Risk of severe hyperkalemia. * **ACE inhibitors/ARBs:** Synergistic risk of hyperkalemia. * **NSAIDs:** May reduce natriuretic effect and increase risk of renal impairment and hyperkalemia. * **Digoxin:** May increase half-life and interfere with serum level assays. * **Lithium:** May increase lithium levels via reduced clearance. ## Monitoring * **Potassium:** Baseline, within 1 week of initiation or dose change, and monthly for the first 3 months. * **Renal Function (SCr/CrCl):** Monitor concurrently with potassium. * **Blood Pressure:** Monitor for orthostasis, particularly in elderly patients. ## Clinical Pearls * **Timing:** Administer in the morning to prevent nocturia. * **Hyperkalemia Risk:** The risk is elevated in patients with stage 3-5 CKD or those on ACEi/ARB therapy. Discontinue if potassium exceeds 5.5 mEq/L. * **Endocrine substitution:** If anti-androgen therapy is desired but gynecomastia occurs, consider eplerenone, which is more selective and lacks affinity for androgen/progesterone receptors. *** *Disclaimer: This information is for educational purposes and does not replace professional clinical judgment. Always verify dosages, contraindications, and drug interactions against current institutional protocols and the official product monograph (FDA label) before prescribing or administering medication.*