Fenoldopam

Summary

Fenoldopam is a medication used primarily in hospital settings to lower blood pressure, and may be given acutely to treat hypertensive emergencies. Fenoldopam is also used in post-operative patients to lower blood pressure and improve kidney function.

It works by activating D1 dopamine receptors in the body to cause vasodilation. Specifically, fenoldopam causes vasodilation in the renal arteries, which can increase blood flow to the kidneys. Fenoldopam also increases natriuresis. 

While the lowering of blood pressure is a good thing in treating patients with high blood pressure, fenoldopam may lower the blood pressure too much to cause hypotension as a side effect. Other side effects include nausea or vomiting, headache, and flushing. Fenoldopam can also cause tachycardia.

Key Points

• Fenoldopam
  • Clinical Use
    • Hypertensive emergency
      • Vasodilation reduces systemic vascular resistance, decreasing BP
        • Think: removing thumb from garden hose removes resistance, which reduces pressure of contents inside
    • Treats Hypertension (Lowers BP)
      • Used post-operatively
  • Mechanism
    • Selective Dopamine D1 receptor agonist
      • FenolDOPAM is a DOPAMine derivative
      • No effect on alpha- or beta-adrenergic receptors, unlike other dopamine derivatives
    • Vasodilator
      • Causes coronary, peripheral, renal, and splanchnic vasodilation
      • Increases renal perfusion (dilates renal arteries)
        • Increased natriuresis and diuresis especially helpful for patients with renal insufficiency
        • Only available agent that improves renal perfusion while lowering blood pressure.
      • D1 signaling activates adenylyl cyclase, increasing cAMP, which eventually causes smooth muscle relaxation
    • Increases Natriuresis
    • Must be given IV
      • Rapid onset of less than 10 minutes
      • Short half-life of 5 minutes
  • Side Effects
    • Hypotension
    • Tachycardia
    • Flushing
    • Headache
    • Nausea