What is the starting dose of Aldactone (spironolactone)?

Starting Dose of Aldactone (Spironolactone)

The starting dose of spironolactone (Aldactone) is 12.5 to 25 mg once daily, with subsequent dose adjustments based on patient response and tolerance. 1, 2

Dosing by Indication

Heart Failure

• Initial dose: 12.5 to 25 mg once daily 1
• For patients with concerns about hyperkalemia or marginal renal function (eGFR 30-49 mL/min/1.73m²): Consider 25 mg every other day or 12.5 mg daily 1, 2
• Maintenance dose (after 4 weeks if K+ ≤5.0 mEq/L):
  • eGFR ≥50: Up to 50 mg once daily
  • eGFR 30-49: 12.5 to 25 mg once daily 1

Hypertension

• Initial dose: 25 to 100 mg daily (single or divided doses) 2
• Titrate at two-week intervals as needed
• Maximum dose: 100 mg/day (doses >100 mg generally don't provide additional blood pressure reduction) 2, 3

Edema in Cirrhosis

• Initial dose: 100 mg daily (range 25-200 mg) 2
• For first episode of ascites: Start with 50-100 mg daily 1
• For recurrent ascites: Consider combination therapy with loop diuretics 1
• Titrate slowly in hospital setting for cirrhosis patients 2

Primary Hyperaldosteronism

• Initial dose: 12.5-25 mg daily 4
• Maintenance dose: 100-400 mg daily 2, 4

Monitoring Protocol

Before Initiation

• Verify baseline potassium ≤5.0 mEq/L
• Verify creatinine ≤2.5 mg/dL in men or ≤2.0 mg/dL in women (or eGFR >30 mL/min/1.73m²) 1
• Discontinue potassium supplements or reduce if patient has history of hypokalemia 1

After Initiation

• Check potassium and renal function within 2-3 days
• Recheck at 7 days after initiation
• Monthly monitoring for first 3 months
• Every 3 months thereafter 1

Precautions and Contraindications

• Hyperkalemia risk: Avoid in patients with baseline K+ >5.0 mEq/L 1
• Renal insufficiency: Avoid in patients with eGFR <30 mL/min/1.73m² 1
• Drug interactions:
  • Avoid triple therapy with ACE inhibitors and ARBs due to hyperkalemia risk 1
  • Caution with NSAIDs and COX-2 inhibitors (can worsen renal function) 1
• Special situations:
  • Instruct patients to temporarily stop medication during episodes of diarrhea or dehydration 1
  • Counsel patients to avoid high-potassium foods 1

Dose Adjustments for Adverse Effects

• Hyperkalemia (K+ >5.5 mEq/L): Reduce dose or switch to alternate-day dosing 5
• Severe hyperkalemia (K+ >6.0 mEq/L): Stop medication immediately 5
• Worsening renal function: Reduce dose or discontinue based on severity 5
• Gynecomastia: Consider switching to eplerenone (25 mg daily) 5

Common Pitfalls to Avoid

1. Starting with too high a dose: Begin with 12.5-25 mg to minimize side effects, especially in elderly or those with renal impairment
2. Inadequate monitoring: Failure to check potassium and renal function within first week can miss early hyperkalemia
3. Continuing potassium supplements: Always discontinue or reduce potassium supplements when starting spironolactone
4. Ignoring drug interactions: Be cautious with concomitant ACE inhibitors, ARBs, NSAIDs
5. Failure to counsel patients: Patients must understand to temporarily stop medication during illness causing dehydration

By following these guidelines, you can safely initiate spironolactone therapy while minimizing the risk of adverse effects, particularly hyperkalemia and renal dysfunction.