Management of Milrinone Therapy

Administration and Monitoring

• Administer fluid boluses (5 mL/kg of isotonic crystalloid or colloid) if not contraindicated, as recommended by the American College of Critical Care Medicine 1
• Avoid loading doses in hemodynamically unstable patients or divide the bolus into five equal aliquots administered over 10 minutes each, according to the American College of Critical Care Medicine 1
• Milrinone has a long half-life (1-10 hours depending on organ function), which can lead to persistent toxicity for 3-30 hours after discontinuation, as noted by the American College of Critical Care Medicine 1
• The recommended loading dose of milrinone is 25-75 μg/kg over 10-20 minutes, and a maintenance infusion of 0.375-0.75 μg/kg/min, with dosage adjustments for renal impairment, as supported by the American College of Cardiology/American Heart Association and the European Society of Cardiology 2, 3, 4, 5, 6, 7
• The following table outlines the recommended infusion rates for milrinone based on creatinine clearance:

• Continuous ECG monitoring is required during infusion and for 1-2 hours after discontinuation, with daily laboratory monitoring of electrolytes, BUN, and creatinine, and hemodynamic monitoring to assess response, as recommended by the American Heart Association and the European Society of Cardiology 8, 3, 4, 5, 6, 7

Discontinuation and Contraindications

• Discontinue milrinone at first sign of significant arrhythmias, as recommended by the American College of Critical Care Medicine 1
• Consider vasopressors such as norepinephrine (0.05-3.3 μg/kg/min) or vasopressin for persistent hypotension, according to the American College of Obstetricians and Gynecologists 9
• Milrinone may cause increased frequency of ventricular arrhythmias, including nonsustained ventricular tachycardia and atrial fibrillation, in patients with cardiovascular conditions, as reported by the American College of Cardiology 7
• Significant vasodilatory effects of milrinone can cause treatment-related hypotension, which should be monitored closely in patients with cardiovascular disease, as recommended by the European Society of Cardiology 10
• Alternative inotropic support options include dobutamine at a dosage of 2.5-5.0 μg/kg/min, which can improve right ventricular output with less hypotensive effect than milrinone, and norepinephrine at a dosage of 0.05-3.3 μg/kg/min to maintain systemic vascular resistance, as recommended by the American Heart Association and the European Society of Cardiology 9, 11, 12, 13
• Major adverse effects of milrinone include hypotension, ventricular arrhythmias, and thrombocytopenia, and milrinone is not recommended for routine use in normotensive patients without evidence of decreased organ perfusion, with a strength of evidence level of IIa, indicating that the benefit of milrinone is greater than or equal to the risk, but the evidence is not as strong as level I, as reported by the American College of Cardiology and the European Society of Cardiology 4, 6, 7, 5

Special Considerations

• Euvolemia with a central venous pressure of 8-12 mmHg is preferred, and excessive fluid administration should be avoided as it can worsen right ventricular distention, according to the American College of Cardiology 14
• Vasopressin may be considered for additional vasopressor support if needed, and inhaled nitric oxide (5-40 ppm) provides selective pulmonary vasodilation without systemic effects, as supported by the American Heart Association and the European Society of Cardiology 9, 12