Milrinone Dosage for Heart Failure
For patients with heart failure, milrinone should be administered with a loading dose of 50 mcg/kg given slowly over 10 minutes, followed by a continuous infusion of 0.375-0.75 mcg/kg/min, with dosage adjustments based on hemodynamic response and renal function. 1
Standard Dosing Protocol
Loading Dose
- 50 mcg/kg administered slowly over 10 minutes 1
- May be given undiluted or diluted to a total volume of 10-20 mL for easier visualization of injection rate 1
Maintenance Infusion
The European Society of Cardiology recommends a loading dose of 25-75 μg/kg over 10-20 minutes, which is consistent with the FDA-approved dosing 2, 3.
Dosage Adjustment for Renal Impairment
Renal impairment significantly increases the terminal elimination half-life of milrinone, necessitating dose adjustments 1:
| Creatinine Clearance (mL/min/1.73m²) | Recommended Infusion Rate (mcg/kg/min) |
|---|---|
| 5 | 0.2 |
| 10 | 0.23 |
| 20 | 0.28 |
| 30 | 0.33 |
| 40 | 0.38 |
| 50 | 0.43 |
Administration Guidelines
Dilution: Milrinone should be diluted prior to maintenance dose administration using:
- 0.45% Sodium Chloride Injection USP
- 0.9% Sodium Chloride Injection USP
- 5% Dextrose Injection USP 1
Concentration: The recommended concentration for infusion is 200 mcg/mL 1
Monitoring:
Titration: Dosage should be titrated based on hemodynamic response and should not exceed 1.13 mg/kg/day 1
Clinical Considerations
Indications
Milrinone is indicated for:
- Acute decompensated heart failure with severe systolic dysfunction
- Low cardiac output states with evidence of end-organ hypoperfusion
- Patients with systolic blood pressure >90 mmHg 3
Special Populations
- Beta-blocker therapy: Milrinone maintains effectiveness during beta-blocker therapy and causes less tachycardia than dobutamine 3
- Refractory heart failure: The American College of Cardiology/American Heart Association guidelines recommend intravenous milrinone (50 μg/kg loading dose, then 0.375 to 0.75 μg/kg per min) for patients with refractory heart failure 2
Efficacy
Clinical studies have demonstrated that milrinone produces significant hemodynamic improvements:
- 28-38% increase in cardiac index
- 24-28% decrease in pulmonary capillary wedge pressure
- These effects occur within 15 minutes of loading dose administration 5, 4
Safety Considerations
- Hypotension: Monitor blood pressure closely, especially during loading dose administration
- Arrhythmias: Increased risk of ventricular arrhythmias has been documented 4
- Duration: The optimal duration of therapy depends on patient responsiveness, but studies have shown efficacy with 48-hour infusions 4, 6
Weaning Protocol
Gradual tapering of milrinone is essential to prevent hemodynamic deterioration. Simultaneous optimization of oral vasodilator therapy during weaning is necessary 3.
By following these dosing guidelines and monitoring protocols, milrinone can be effectively and safely administered to patients with heart failure, providing significant improvements in hemodynamics and symptoms.