What are the usage guidelines for Spironolactone?

Spironolactone Usage Guidelines

Spironolactone should be initiated at a dose of 12.5 to 25 mg daily for heart failure, 25-100 mg daily for hypertension, 100 mg daily for edema in cirrhosis, and 50-200 mg daily for hormonal conditions like acne or hirsutism, with careful monitoring of potassium levels and renal function. 1, 2

Indications for Use

FDA-Approved Indications

• Heart Failure: NYHA Class III-IV with reduced ejection fraction to increase survival and reduce hospitalizations 2
• Hypertension: As add-on therapy for patients not adequately controlled on other agents 2
• Edema: Management of edema associated with hepatic cirrhosis or nephrotic syndrome 2
• Primary Hyperaldosteronism: 100-400 mg daily for preparation for surgery or long-term management 2

Common Off-Label Uses

• Female Pattern Hair Loss: 50-200 mg daily 3
• Acne in Women: 50-200 mg daily, with significant improvement in 70-85% of patients 1, 4
• Hirsutism: 100-200 mg daily 5

Dosing Guidelines by Indication

Heart Failure

• Initial dose: 25 mg once daily (if serum K+ ≤5.0 mEq/L and eGFR >50 mL/min) 1, 2
• Titration: May increase to 50 mg daily if tolerated 2
• Dose adjustment: Reduce to 25 mg every other day if hyperkalemia develops 2
• Renal impairment: For eGFR 30-50 mL/min, start with 25 mg every other day 2

Hypertension

• Initial dose: 25-100 mg daily (single or divided doses) 2
• Titration: Adjust at 2-week intervals 2
• Maximum dose: Doses >100 mg/day generally don't provide additional blood pressure reduction 2, 6

Edema in Cirrhosis

• Initial dose: 100 mg daily (range 25-200 mg) 2
• Setting: Initiate therapy in hospital setting and titrate slowly 2
• Duration: Administer for at least 5 days before increasing dose 2
• Caution: Stop diuretics if serum sodium <120 mmol/L 1

Acne/Hirsutism in Women

• Initial dose: 50 mg daily 4
• Titration: May increase to 100 mg daily after 6 weeks 4
• Duration: Treatment may continue for months to years 3
• Efficacy: 81.9% of women report improvement in acne at 24 weeks 4

Monitoring Guidelines

Initial Monitoring

• Baseline tests: Serum potassium, sodium, and renal function 1, 2
• Early follow-up: Recheck potassium and renal function within 3 days and at 1 week after initiation 1

Ongoing Monitoring

• First 3 months: Monthly monitoring of potassium and renal function 1
• Maintenance: Every 3 months thereafter 1
• Special situations: New cycle of monitoring when adding or increasing ACEIs or ARBs 1

Action Thresholds

• Hyperkalemia: If K+ >5.5 mEq/L, discontinue or reduce dose 1
• Renal dysfunction: If significant increase in serum creatinine, evaluate entire regimen and consider stopping spironolactone 1

Precautions and Contraindications

Contraindications

• Acute renal failure or significant renal impairment 2
• Addison's disease 2
• Hyperkalemia 2
• Concomitant use of eplerenone or triamterene 2
• Pregnancy (Category C) - potential feminization of male fetuses 3, 2

Drug Interactions

• Avoid triple combination: ACEIs, ARBs, and spironolactone due to hyperkalemia risk 1
• Use caution with: Potassium supplements, NSAIDs, COX-2 inhibitors 1
• Instruct patients: Stop spironolactone during episodes of diarrhea or when loop diuretic therapy is interrupted 1

Adverse Effects

Common Side Effects

• Endocrine: Gynecomastia or breast pain (10% of men) 1, 7
• Menstrual: Irregular menses (15-30% of women) 3
• Electrolyte: Hyperkalemia (up to 24% in some populations) 1
• Other: Diuresis (29%), headaches (20%), dizziness (3-4%) 3, 4

Serious Adverse Effects

• Hyperkalemia: Can be severe, especially in patients with renal dysfunction or taking other potassium-sparing medications 1
• Renal impairment: Monitor for worsening renal function 2

Special Populations

Elderly

• Higher risk of hyperkalemia; consider lower starting doses and more frequent monitoring 1

Renal Impairment

• For eGFR 30-50 mL/min, start with 25 mg every other day 2
• Avoid in severe renal impairment 2

Women of Childbearing Age

• Consider concomitant use of reliable contraception 3
• Combined oral contraceptives can help regulate menstrual cycles while on spironolactone 3

Long-Term Safety

• No increased risk of breast, ovarian, uterine, or cervical cancer with long-term use 3, 8
• Studies have followed patients for up to 8 years without serious adverse effects 3

By following these guidelines and implementing appropriate monitoring, spironolactone can be used effectively and safely across multiple indications.