Recommended Dosage of Milrinone
The recommended dosage of milrinone is a loading dose of 50 mcg/kg administered 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 or 20 mL for easier visualization of injection rate 1
Maintenance Infusion
- Minimum: 0.375 mcg/kg/min (0.59 mg/kg/day) 1
- Standard: 0.5 mcg/kg/min (0.77 mg/kg/day) 1
- Maximum: 0.75 mcg/kg/min (1.13 mg/kg/day) 1
Dosage Adjustment for Renal Impairment
Renal function significantly affects milrinone clearance, requiring dose adjustments:
| 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
- Milrinone should be diluted prior to maintenance infusion 1
- Compatible diluents include 0.45% Sodium Chloride Injection, 0.9% Sodium Chloride Injection, or 5% Dextrose Injection 1
- Use a calibrated electronic infusion device for administration 1
- Titrate based on hemodynamic response 1
- Total daily dose should not exceed 1.13 mg/kg/day 1
Clinical Considerations
Indications
- Acute decompensated heart failure with severe systolic dysfunction 2
- Low cardiac output states with evidence of end-organ hypoperfusion 2
- Patients with systolic blood pressure >90 mmHg 2
- Refractory heart failure when other treatments have failed 3
Hemodynamic Effects
- Increases cardiac index by 21-31% 2
- Decreases pulmonary capillary wedge pressure by 13-41% 2
- Effects begin within 15 minutes of administration 2
- Combines positive inotropic and vasodilatory properties 2, 4
Monitoring Requirements
- Continuous hemodynamic monitoring during infusion 2
- ECG monitoring due to potential arrhythmogenic effects 2
- Monitor for 1-2 hours after discontinuation 2
- Infusion rate should be adjusted according to hemodynamic and clinical response 1
Potential Adverse Effects
- Hypotension, particularly with rapid administration of loading dose 2, 5
- Ventricular arrhythmias 2, 6
- Thrombocytopenia 2
- Potential increased risk of mortality with long-term use 2
Important Considerations
- Milrinone maintains effectiveness during beta-blocker therapy, making it suitable for patients on concomitant beta-blocker therapy who may have inadequate response to dobutamine 2
- Gradual tapering is essential to prevent hemodynamic deterioration 2
- The American College of Cardiology recommends against routine use of parenteral inotropes in normotensive patients without evidence of decreased organ perfusion 2
- Milrinone is primarily cleared by the kidneys, necessitating dose adjustments in renal impairment 1, 5
Following these dosing guidelines will help optimize the hemodynamic benefits of milrinone while minimizing potential adverse effects in patients with heart failure.