What is the recommended dosage of Lasilactone (Spironolactone/Hydrochlorothiazide) for a patient with heart failure and an ejection fraction of 37%?

Lasilactone Dosing for Heart Failure with EF 37%

For a patient with heart failure and an ejection fraction of 37%, the recommended dosage of Lasilactone (spironolactone/hydrochlorothiazide) is 1/2 tablet (10mg/25mg) daily initially, with potential titration to 1 tablet (20mg/50mg) daily if tolerated and clinically indicated. 1, 2

Rationale for Dosing Recommendation

• An EF of 37% falls into the reduced ejection fraction category (<50%), requiring specific heart failure management strategies 1
• For patients with reduced EF (<50%), low-dose loop diuretics and mineralocorticoid receptor antagonists (MRAs) like spironolactone should be considered to improve symptoms and reduce hospitalization risk 1
• The FDA-approved starting dose for spironolactone in heart failure is 25mg once daily, but lower doses may be appropriate when combined with hydrochlorothiazide in Lasilactone 2

Dosing Strategy

• Start with 1/2 tablet (10mg spironolactone/25mg hydrochlorothiazide) daily 2
• Monitor for:
  • Renal function and electrolytes (particularly potassium) at 1-2 weeks after initiation 1, 2
  • Blood pressure and clinical status (symptoms, signs of congestion, body weight) 1
  • Heart rate and overall tolerance 1
• If well tolerated after 2-4 weeks with stable renal function and potassium levels, consider uptitration to 1 tablet daily 1, 2

Special Considerations

• If serum potassium rises above 5.0 mEq/L, reduce dose to 1/2 tablet every other day 2
• In patients with eGFR between 30-50 mL/min/1.73m², consider more cautious dosing (1/2 tablet every other day) due to increased hyperkalemia risk 2
• Patients with heart failure and reduced EF should receive comprehensive therapy including:
  • ACE inhibitor or ARB 1
  • Beta-blocker 1
  • MRA (spironolactone component of Lasilactone) 1

Monitoring Requirements

• Check renal function and electrolytes:
  • 1-2 weeks after initiation 1, 2
  • 1-2 weeks after each dose increase 1, 2
  • Every 3-6 months during maintenance therapy 1, 2
• More frequent monitoring is required in patients with:
  • History of renal dysfunction 1
  • Electrolyte abnormalities 1, 2
  • Age ≥75 years 3

Efficacy Considerations

• Even lower than target doses of spironolactone (approximately 20mg/day) have shown benefit in heart failure patients 3
• Patients with reduced EF benefit from MRAs through reduced hospitalization and mortality risk 2
• The diuretic component helps manage fluid retention and congestion symptoms 1

Common Pitfalls and Caveats

• Hyperkalemia risk increases with higher doses, especially in patients with reduced renal function 2, 3
• Discontinuation rates of spironolactone can reach 25-30% in the first year, particularly in high-risk groups (elderly, renal dysfunction) 3
• Discontinuation of therapy is associated with 2-4 fold higher risk of subsequent heart failure events; therefore, maintaining even a lower dose is preferable to discontinuation 3
• Worsening renal function may occur but doesn't necessarily require discontinuation if mild and potassium remains controlled 4

Dose Adjustment Algorithm

1. If potassium rises to >5.0-5.5 mEq/L: Reduce to 1/2 tablet every other day 2
2. If potassium rises >5.5 mEq/L: Temporarily hold medication and consult specialist 2
3. If renal function worsens (>30% increase in creatinine): Reduce dose and monitor closely 4
4. If symptoms of congestion worsen: Consider temporary increase in hydrochlorothiazide component or addition of loop diuretic 1