Please check your internet connection and try again.
# Aldactone (spironolactone)
## Overview
Spironolactone is a potassium-sparing diuretic and a competitive aldosterone receptor antagonist. It inhibits sodium reabsorption in the distal convoluted tubule and collecting duct, promoting sodium/water excretion while retaining potassium.
## Primary Indications
* Heart failure (NYHA Class II-IV, reduced ejection fraction)
* Edema (cirrhosis, nephrotic syndrome)
* Primary hyperaldosteronism (Conn's syndrome)
* Essential hypertension (typically add-on therapy)
## Adult Dosing
* **Heart Failure:** 12.5–25 mg once daily. Target dose 25 mg daily.
* **Hypertension:** 25–100 mg daily in single or divided doses.
* **Edema (Cirrhosis/Nephrotic syndrome):** 100 mg daily initially, titrated based on response (range: 25–200 mg/day). Doses >100 mg/day require careful monitoring.
* **Primary Hyperaldosteronism:** 100–400 mg daily for pre-operative preparation; use the lowest effective dose for long-term management.
## Pediatric Dosing
* **Heart Failure:** 1–3 mg/kg/day divided once or twice daily (max 25 mg/day).
* **Diuretic/Antihypertensive:** 1–3.3 mg/kg/day divided twice daily (max 100 mg/day).
* *Note: Dosing based on local institutional protocols is recommended due to variability in pediatric clinical practice.*
## Dose Adjustments
* **Renal Impairment:** Avoid if eGFR <30 mL/min/1.73m² (increased risk of hyperkalemia).
* **Hepatic Impairment:** Reduce dose in severe hepatic disease; monitor for fluid/electrolyte changes.
## Contraindications
* Hyperkalemia (K+ >5.5 mEq/L)
* Concomitant use of eplerenone or potassium supplements
* Addison’s disease
* Anuria
* Severe renal impairment (eGFR <30 mL/min/1.73m²)
## Adverse Effects
* **Common:** Hyperkalemia, dizziness, fatigue, GI upset.
* **Endocrine (due to anti-androgenic effects):** Gynecomastia (dose-dependent), breast pain, erectile dysfunction, menstrual irregularities.
* **Serious:** Severe hyperkalemia (cardiac arrhythmias), hyponatremia.
## Key Drug Interactions
* **ACE Inhibitors/ARBs/Renin Inhibitors:** Increases risk of hyperkalemia significantly.
* **Potassium Supplements/Salt Substitutes:** Contraindicated.
* **NSAIDs:** May reduce diuretic efficacy and increase risk of renal impairment/hyperkalemia.
* **Digoxin:** May alter serum levels; monitor closely for toxicity.
* **Lithium:** May decrease lithium clearance, leading to toxicity.
## Monitoring
* **Serum Potassium:** Before initiation, within 1 week of starting or titrating, and periodically thereafter (more frequently in patients with renal impairment).
* **Renal Function (SCr/BUN/eGFR):** Baseline and at least annually.
* **Blood Pressure:** Monitor for orthostasis.
## Clinical Pearls
* **Potassium Threshold:** If K+ exceeds 5.0–5.5 mEq/L, the dose should be reduced or held, and serum levels should be re-checked.
* **Administration:** Take with food to reduce GI irritation and potentially increase bioavailability.
* **Time to Effect:** Diuretic effects may take up to 3 days to peak; antihypertensive effects may take weeks.
* **Substitution:** If gynecomastia occurs, consider switching to eplerenone, which is more selective and lacks anti-androgenic side effects.
***
*Disclaimer: This information is for educational purposes for healthcare professionals. Dosing, contraindications, and drug interactions can change. Always verify current prescribing information in a trusted clinical resource (e.g., Lexicomp, UpToDate) and adhere to local institutional clinical protocols before prescribing or administering medication.*
