What are the indications and usage guidelines for Aldactone (spironolactone)?

Indications and Usage Guidelines for Aldactone (Spironolactone)

Spironolactone is primarily indicated for heart failure (NYHA Class III-IV), hypertension, edema associated with hepatic cirrhosis or nephrotic syndrome, and primary hyperaldosteronism, with specific dosing regimens and monitoring requirements for each condition. 1

Heart Failure

• Indicated for NYHA Class III-IV heart failure with reduced ejection fraction to increase survival, manage edema, and reduce hospitalization 1
• Treatment with spironolactone led to a 30% relative risk reduction in death and 35% reduction in hospital admissions for worsening heart failure 2
• Recommended for patients with left ventricular ejection fraction ≤35% and moderate to severe symptoms (NYHA class III-IV) 2
• Usually administered in conjunction with other heart failure therapies including ACE inhibitors and beta-blockers 1, 2

Dosing in Heart Failure:

• Initial dose: 25 mg once daily (or 25 mg every other day in patients with eGFR 30-50 mL/min) 1
• May increase to 50 mg daily if tolerated and clinically indicated 1
• Reduce to 25 mg every other day if hyperkalemia develops 1

Hypertension

• Indicated as add-on therapy for treatment of hypertension when blood pressure is not adequately controlled on other agents 1
• Initial daily dose: 25-100 mg administered in single or divided doses 1
• Can be titrated at two-week intervals; doses greater than 100 mg/day generally do not provide additional blood pressure reduction 1

Edema Associated with Liver Cirrhosis

• First-line diuretic for treatment of ascites due to cirrhosis 3, 2
• Inhibits secondary hyperaldosteronism that causes sodium and water reabsorption in distal renal tubule 2
• Initial daily dose: 100 mg (range 25-200 mg) administered in single or divided doses 1
• For cirrhosis patients, therapy should be initiated in a hospital setting with slow titration 1
• Monotherapy with spironolactone is effective in controlling ascites in cirrhosis; loop diuretics can be added if response is insufficient 2
• High-dose therapy (300-600 mg daily) may be effective in patients with relatively refractory ascites 4

Primary Hyperaldosteronism

• Dosage: 100-400 mg daily in preparation for surgery 1
• Can be used as long-term maintenance therapy at lowest effective dosage for patients unsuitable for surgery 1
• Treatment of first choice in idiopathic hyperaldosteronism and preoperative management of aldosterone-producing adenoma 5

Off-Label Use in Women with Acne

• Used off-label for acne vulgaris in females at doses of 50-200 mg daily 2

Monitoring Requirements

For All Patients:

• Check renal function and serum electrolytes before starting treatment 2
• Re-check renal function and electrolytes 1 and 4 weeks after starting treatment 2
• Continue monitoring at 1,2,3, and 6 months after achieving maintenance dose, then every 6 months 2

Special Considerations:

• Monitor for hyperkalemia, especially in elderly patients or those with renal impairment 2
• Discontinue potassium supplements when initiating spironolactone 2
• Avoid triple combination of ACE inhibitors, ARBs, and spironolactone due to hyperkalemia risk 2
• Caution patients to avoid NSAIDs and high-potassium foods 2

Adverse Effects and Contraindications

Major Adverse Effects:

• Hyperkalemia (especially in patients with renal impairment) 2, 6
• Gynecomastia and breast tenderness in men (10% of patients) 2
• Menstrual irregularities in women 2
• Decreased libido and erectile dysfunction in men 2
• Potential worsening of renal function 2

Contraindications:

• Acute renal failure 2
• Addison's disease 2
• Existing hyperkalemia 2
• Anuria 2
• Concomitant use with eplerenone or triamterene 2
• Significant renal impairment 2

Management of Adverse Effects:

• If potassium rises to >5.5 mmol/L, halve the dose (e.g., to 25 mg on alternate days) 2
• If potassium rises to >6.0 mmol/L, stop spironolactone immediately 2
• If creatinine rises to >220 μmol/L (2.5 mg/dL), halve the dose 2
• If creatinine rises to >310 μmol/L (3.5 mg/dL), stop spironolactone immediately 2
• For breast tenderness/enlargement in men, consider switching to eplerenone 2

Spironolactone has a long half-life and slow onset of action, requiring 3-5 days to achieve stable concentration and full natriuretic effect 3, 2. The medication can be taken with or without food, but should be taken consistently with respect to food 1.