Milrinone Carinopharm (Milrinone)

Milrinone is a phosphodiesterase‑3 inhibitor used in acute cardiac care.

• Acute decompensated heart failure: improves cardiac output and reduces pulmonary congestion.
• Cardiogenic shock: provides rapid inotropic support and vasodilation to stabilize blood pressure.
• Low cardiac output after cardiac surgery: enhances myocardial contractility to aid hemodynamic recovery.

• Milrinone selectively inhibits phosphodiesterase‑3 enzymes, leading to an accumulation of intracellular cyclic AMP in cardiac myocytes and vascular smooth‑muscle cells. The rise in cAMP enhances calcium influx during systole, producing a positive inotropic effect, while simultaneously causing vasodilation through smooth‑muscle relaxation, thereby improving cardiac output and reducing afterload.

Milrinone may cause a range of adverse reactions that clinicians monitor during therapy.

Common Side Effects

• Hypotension: reduction in systemic blood pressure.
• Headache: mild to moderate intensity.
• Arrhythmia: premature ventricular or atrial beats.
• Nausea: occasional gastrointestinal upset.

Serious or Rare Side Effects

• Severe arrhythmias: ventricular tachycardia or fibrillation.
• Myocardial ischemia: chest pain or ECG changes.
• Severe hypotension: profound drop in blood pressure requiring intervention.

Milrinone requires careful monitoring and specific clinical considerations.

• Monitor blood pressure: watch for hypotension, especially during initiation.
• Monitor cardiac rhythm: observe for new or worsening arrhythmias.
• Adjust dose in renal impairment: reduce infusion rate in patients with decreased clearance.
• Use cautiously after recent myocardial infarction: assess risk of ischemia.
• Avoid in severe aortic stenosis: may precipitate hemodynamic collapse.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Milrinone can interact with several drug classes, necessitating vigilance.

Major Interactions (Avoid)

• Concomitant use with other PDE3 inhibitors: additive inotropic and vasodilatory effects may cause severe hypotension.
• Strong CYP3A4 inhibitors (e.g., ketoconazole): increase plasma concentrations, raising toxicity risk.
• Potent vasodilators (e.g., nitroprusside): may produce profound hypotension.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may blunt desired inotropic response.
• Digoxin: combined effect on cardiac contractility requires ECG monitoring.
• Diuretics and ACE inhibitors: monitor electrolytes and renal function.