Milnocor (Milrinone)

Milrinone acts as a cardiac inotropic and vasodilator in severe heart failure syndromes.

• Acute decompensated heart failure: increases cardiac output and reduces pulmonary congestion.
• Cardiogenic shock: provides rapid inotropic support to maintain systemic perfusion.
• Post‑cardiac surgery low cardiac output: improves myocardial performance during the immediate postoperative period.

• Milrinone selectively inhibits phosphodiesterase‑3 enzymes, preventing the breakdown of cyclic adenosine monophosphate (cAMP) within cardiac myocytes and vascular smooth‑muscle cells. Elevated intracellular cAMP enhances calcium influx during systole, producing a positive inotropic effect, while also promoting relaxation of vascular smooth muscle, resulting in vasodilation and reduced afterload.

Milrinone may cause a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Hypotension: reduction in systemic blood pressure.
• Tachyarrhythmias: accelerated heart rhythm including atrial fibrillation.
• Headache: mild to moderate discomfort.
• Nausea: gastrointestinal upset.

Serious or Rare Side Effects

• Ventricular tachycardia or fibrillation: life‑threatening arrhythmias.
• Severe hypotension: marked drop in blood pressure requiring intervention.
• Myocardial ischemia: reduced coronary perfusion.
• Allergic reactions: rash, bronchospasm, or anaphylaxis.

Milrinone requires careful clinical monitoring due to its potent cardiovascular effects.

• Cardiac monitoring: continuous ECG and hemodynamic assessment are essential.
• Electrolyte balance: correct potassium and magnesium levels to reduce arrhythmia risk.
• Renal function: adjust dosing in patients with impaired clearance.
• Concomitant vasodilators: avoid or use with caution to prevent excessive hypotension.
• Contraindications: do not use in patients with obstructive hypertrophic cardiomyopathy.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Milrinone can interact with several drug classes, influencing its safety and efficacy.

Major Interactions (Avoid)

• Other phosphodiesterase‑3 inhibitors: additive inotropic and vasodilatory effects.
• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole): increase plasma milrinone concentrations.
• Potent vasodilators (e.g., nitroprusside): risk of severe hypotension.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may blunt the inotropic response, requiring hemodynamic monitoring.
• Diuretics: electrolyte shifts can predispose to arrhythmias; monitor serum levels.
• ACE inhibitors or ARBs: additive blood‑pressure lowering effects, observe for hypotension.