Please check your internet connection and try again.
# Aldactone (spironolactone)
## Overview
Spironolactone is a potassium-sparing diuretic and a potent aldosterone receptor antagonist. It acts primarily in the distal renal tubules to inhibit sodium reabsorption and potassium excretion.
## Primary Indications
* Heart failure (HFrEF)
* Edema associated with hepatic cirrhosis or nephrotic syndrome
* Primary hyperaldosteronism (Conn’s syndrome)
* Essential hypertension
* Off-label: Hirsutism, acne, and androgenic alopecia.
## Adult Dosing
* **Heart Failure (HFrEF):** Initial 12.5–25 mg once daily. Target dose 25–50 mg daily.
* **Edema (Cirrhosis/Nephrotic Syndrome):** 100 mg daily; may titrate up to 400 mg daily based on response.
* **Primary Hyperaldosteronism:** 100–400 mg daily prior to surgery; use lowest effective dose for long-term maintenance.
* **Hypertension:** 25–100 mg daily in single or divided doses.
## Pediatric Dosing
* **Heart Failure (off-label):** 1–3.3 mg/kg/day divided once or twice daily. Max: 50 mg/day.
* **Edema/Hypertension (off-label):** 1–3.3 mg/kg/day divided once or twice daily. Max: 100 mg/day.
* *Note: Dosing varies by institutional protocol; confirm with local Pediatric Pharmacopeia.*
## Dose Adjustments
* **Renal Impairment:** Avoid or exercise extreme caution in patients with eGFR <30 mL/min/1.73m² due to increased risk of hyperkalemia.
* **Hepatic Impairment:** Adjust dose in accordance with response and clinical stability; monitor closely for fluid/electrolyte shifts.
## Contraindications
* Anuria
* Acute renal insufficiency or significant renal impairment
* Hyperkalemia (serum potassium >5.0–5.5 mEq/L)
* Addison’s disease
* Concomitant use of eplerenone
## Adverse Effects
* **Hyperkalemia:** Serious, potentially life-threatening.
* **Endocrine:** Gynecomastia, breast tenderness, menstrual irregularities, impotence (due to anti-androgenic effects).
* **GI:** Gastritis, diarrhea, vomiting.
* **CNS:** Drowsiness, headache, confusion.
## Key Drug Interactions
* **Potassium Supplements/Potassium-Sparing Diuretics:** Massive risk of severe hyperkalemia.
* **ACE Inhibitors/ARBs/Renin Inhibitors:** Significantly increase hyperkalemia risk; monitor K+ closely.
* **NSAIDs:** May reduce natriuretic effect and increase risk of renal impairment/hyperkalemia.
* **Digoxin:** Spironolactone may increase digoxin half-life and serum concentrations.
* **Lithium:** May reduce renal clearance of lithium, increasing toxicity risk.
## Monitoring
* **Potassium:** Baseline, within 1 week of initiation/dose change, then monthly for 3 months, then every 3 months.
* **Renal Function (SCr/BUN):** Baseline and regularly per the monitoring schedule above.
* **Blood Pressure:** Monitor during titration.
## Clinical Pearls
* Consider eplerenone if the patient experiences intolerable gynecomastia, as eplerenone is a more selective aldosterone antagonist with less affinity for androgen/progesterone receptors.
* Administer consistently with or without food to maintain steady absorption.
* Advise patients to avoid salt substitutes containing potassium chloride unless approved by a clinician.
***
**Educational Disclaimer:** This information is intended for educational purposes only and does not constitute medical advice. Always verify current prescribing information, institutional protocols, and patient-specific safety factors using primary literature or electronic clinical databases (e.g., Lexicomp, UpToDate) before prescribing or administering medication.
