Milrinone is a selective PDE-3 inhibitor used for short-term treatment of acute heart failure. By blocking PDE3, milrinone increases cAMP levels in the heart, which leads to increased contractility. Milrinone’s inhibition of PDE3 also affects the blood vessels to cause vasodilation. This can result in the adverse effect of hypotension.

Key Points

  • Milrinone
    • Mechanism
      • Selective PDE3 inhibitor
        • Prevents PDE-mediated degradation of of cAMP
    • Clinical Use
      • Acute decompensated heart failure
        • Increased cAMP in cardiomyocytes causes Ca2+ influx
        • Increases contractility (ionotropy) and heart rate (chronotropy)
      • Pulmonary arterial hypertension (PAH)
    • Adverse Effects
      • Arrhythmias
      • Hypotension
        • In vascular smooth muscle, increase in cAMP induces vasodilation, causing decreased SVR and decreased BP