What is Aldactone (spironolactone) used for in family medicine?

Aldactone (Spironolactone) Uses in Family Medicine

Aldactone (spironolactone) is a potassium-sparing diuretic and mineralocorticoid receptor antagonist with several important clinical applications in family medicine. Spironolactone is primarily used for heart failure, hypertension, edema associated with liver cirrhosis or nephrotic syndrome, primary hyperaldosteronism, and acne in women.

Heart Failure

• Indicated for NYHA Class III-IV heart failure with reduced ejection fraction 1
• Improves survival and reduces hospitalization when added to standard therapy (ACE inhibitor and loop diuretic) 2
• Recommended dosing:
  • Starting dose: 12.5-25 mg once daily
  • Target dose: 25-50 mg once daily 2
• Blocks aldosterone effects that promote myocardial fibrosis, potassium depletion, and sympathetic activation 2
• The RALES trial showed marked improvement in survival in advanced heart failure patients 2
• Monitor serum potassium closely, especially when combined with ACE inhibitors 3

Hypertension

• Used as add-on therapy for resistant hypertension 1
• Particularly effective when aldosterone levels are elevated
• Typical dosing for hypertension: 25-50 mg daily 4
• Higher doses (>50 mg/day) do not produce further significant blood pressure reductions 4
• Consider as fourth-line therapy after other agents have failed 4

Edema Management

• Indicated for edema associated with:
  • Hepatic cirrhosis when not responsive to fluid/sodium restriction 1
  • Nephrotic syndrome when other treatments are inadequate 1
• For cirrhosis, higher doses are typically used:
  • Starting dose: 100 mg daily
  • Can be increased up to 400 mg daily if needed 5

Primary Hyperaldosteronism

• First-line medical treatment for bilateral primary aldosteronism 2
• Effective dose usually 50-100 mg once daily, can be titrated up to 300-400 mg if necessary 2
• Controls blood pressure and hypokalemia in most cases 6

Acne in Women

• Not FDA-approved for acne but used off-label 2
• Acts as an antiandrogen by:
  • Decreasing testosterone production
  • Inhibiting testosterone and DHT binding to androgen receptors
  • Possibly inhibiting 5α-reductase 2
• Typical dosing for acne: 50-100 mg daily 2
• Studies show 66-75% improvement in acne severity 2
• Consider for women with hormonal acne patterns, particularly when combined with oral contraceptives 2

Side Effects and Monitoring

• Common side effects:

  • Menstrual irregularities (40.6%) 2
  • Diuresis (29%) 2
  • Breast tenderness (17%) 2
  • Gynecomastia (10% in RALES trial) 2
  • Fatigue, headache, dizziness 2

• Monitoring considerations:

  • Serum potassium monitoring is essential in:
    • Elderly patients
    • Patients with renal or hepatic dysfunction
    • Patients taking ACE inhibitors, ARBs, NSAIDs, or digoxin 2
  • Risk of hyperkalemia increases with doses above 25 mg daily 7
  • Routine potassium monitoring may not be necessary in young, healthy women taking it for acne 2

Contraindications

• Hyperkalemia
• Severe renal insufficiency
• Addison's disease
• Concomitant use of other potassium-sparing diuretics
• Pregnancy (category C) 2

Practical Considerations

• For heart failure, start at lower doses (12.5-25 mg) to minimize risk of hyperkalemia 2
• For acne, consider combining with oral contraceptives to regulate menses and prevent pregnancy 2
• The selective MRA eplerenone may be an alternative with fewer hormonal side effects but is less potent 2
• Spironolactone is more potent than eplerenone as an MR antagonist 2

Remember that close monitoring is essential when initiating therapy, especially in patients with comorbidities or those taking other medications that can affect potassium levels.