What is the recommended dosage of Lasilactone (Spironolactone) for a patient with Heart Failure with Reduced Ejection Fraction (HFrEF)?

Lasilactone (Spironolactone/Furosemide) Dosing in HFrEF with EF 37%

For a patient with HFrEF and EF 37%, Lasilactone (20/50) should be given once daily, not twice daily, as the recommended starting dose of spironolactone in heart failure is 25 mg once daily. 1

Dosing Recommendations

• The FDA-approved starting dose for spironolactone in heart failure is 25 mg once daily, which is close to the 20 mg component in Lasilactone 1
• Lasilactone contains 20 mg furosemide and 50 mg spironolactone per tablet, making once daily dosing appropriate for initial therapy 2
• In the landmark RALES trial, patients with LVEF ≤35% were treated with spironolactone 25 mg once daily, with the mean daily dose at study end being 26 mg 1
• European Society of Cardiology guidelines recommend starting spironolactone at 25 mg once daily in patients with LVEF ≤35% and symptomatic heart failure 3

Titration and Monitoring

• After initiating treatment, recheck renal function and serum electrolytes at 1 week and 4 weeks 3
• Consider dose up-titration after 4-8 weeks if the patient tolerates the medication well 3
• Do not increase the dose if there is worsening renal function or hyperkalemia 3
• The maximum target dose of spironolactone in heart failure is 50 mg once daily, which matches the spironolactone component in Lasilactone 1

Patient Selection Criteria

• Spironolactone is indicated for patients with:
  • LVEF ≤35% (patient has 37%, which is borderline) 3
  • Moderate to severe symptoms (NYHA functional class III-IV) 3
  • Optimal doses of beta-blockers and ACE inhibitors/ARBs 3

Contraindications and Precautions

• Avoid in patients with:
  • Serum potassium >5.0 mEq/L 1
  • Severe renal dysfunction (eGFR <30 mL/min/1.73m²) 1, 4
• Use with caution in elderly patients who are at higher risk for hyperkalemia and worsening renal function 5
• Patients with advanced CKD (eGFR <45 mL/min/1.73m²) showed higher readmission rates with spironolactone use 4

Clinical Benefits

• Spironolactone reduces mortality by 30% and hospitalization for worsening heart failure by 35% in patients with severe HF 3
• The absolute risk reduction in mortality after 2 years of treatment is 11.4%, with a number needed to treat of 9 3
• Even in older patients with HFrEF, spironolactone shows modest but consistent clinical effectiveness 5

Common Pitfalls to Avoid

• Avoid triple combination of ACE inhibitors, ARBs, and aldosterone antagonists due to substantial risk of hyperkalemia 6
• Do not continue spironolactone if serum potassium rises above 5.5 mEq/L or if there is significant worsening of renal function 3
• Monitor for gynecomastia in male patients, which occurs in approximately 10% of patients on spironolactone 3
• Avoid twice daily dosing initially, as this may increase the risk of adverse effects without proven additional benefit 1

In conclusion, for a patient with HFrEF and EF 37%, Lasilactone (20/50) should be initiated at one tablet once daily with appropriate monitoring of renal function and electrolytes. Twice daily dosing is not recommended based on current guidelines and clinical evidence.