Please check your internet connection and try again.
# Spironolactone
## Overview
Spironolactone is a potassium-sparing diuretic and aldosterone antagonist.
## Primary Indications
* Heart failure (NYHA class II-IV) with reduced ejection fraction
* Hypertension (essential)
* Edema associated with cirrhosis or nephrotic syndrome
* Primary hyperaldosteronism
## Adult Dosing
* **Heart Failure:** Initiate at 25 mg once daily. May increase to 50 mg once daily if natriuresis is insufficient or to 100 mg once daily if needed. If initial dose is not tolerated, may reduce to 25 mg every other day.
* **Hypertension:** Initiate at 25-100 mg once daily in 1-2 divided doses. May titrate up to 400 mg daily.
* **Edema (Cirrhosis/Nephrotic Syndrome):** Initiate at 100 mg once daily in 1-2 divided doses. May adjust dose to 25-200 mg daily.
* **Primary Hyperaldosteronism:** Preoperative: 100-400 mg daily in 2-4 divided doses. Long-term maintenance: 25-100 mg daily.
## Pediatric Dosing
* Limited data in pediatric populations. Oral doses are typically 1-3 mg/kg/day divided into 2-4 doses. Maximum doses not well established.
## Dose Adjustments
* No specific dose adjustments needed for renal or hepatic impairment, but caution is advised due to risk of hyperkalemia and fluid/electrolyte imbalances. Monitor closely.
## Contraindications
* Addison's disease
* Anuria
* Hyperkalemia
* Renal insufficiency (significant)
* Concomitant use with eplerenone
## Adverse Effects
* Hyperkalemia
* Hyponatremia
* Gynecomastia, impotence, menstrual irregularities (due to antiandrogenic effects)
* Dizziness, headache
* Gastrointestinal upset (nausea, vomiting, diarrhea)
* Renal dysfunction
## Key Drug Interactions
* **ACE inhibitors, ARBs, eplerenone, potassium supplements, NSAIDs:** Increased risk of hyperkalemia.
* **Digoxin:** Spironolactone can increase serum digoxin levels.
* **Lithium:** Spironolactone can reduce renal clearance of lithium, increasing lithium toxicity risk.
## Monitoring
* Serum potassium (frequently, especially at initiation, dose changes, or in renal impairment)
* Electrolytes (sodium)
* Renal function (BUN, creatinine)
* Blood pressure
* Signs and symptoms of hyperkalemia (muscle weakness, palpitations)
* Gynecomastia or menstrual irregularities
## Clinical Pearls
* Administer with food to improve absorption and reduce GI upset.
* Long-term therapy may require dose adjustments based on electrolyte and renal function.
* Consider in patients with resistant hypertension.
* Careful monitoring of potassium is crucial, especially in patients with impaired renal function or those on concurrent medications that increase potassium.
***
*Please verify current prescribing information with the latest official product monograph or trusted drug compendium.*
