Medicine & USMLE


Cardio Drugs - Blood Pressure
  1. ACE Inhibitors
  2. Angiotensin II Receptor Blockers (ARBs)
  3. Beta Blockers: Mechanisms and Clinical Uses
  4. Beta Blockers: Side Effects
  5. DHP Calcium Channel Blockers
  6. Hydralazine
  7. Aliskiren
  8. Nitroprusside
  9. Alpha-1 Blockers
  10. Clonidine


Nitroprusside is a medication used to lower blood pressure in order to treat hypertensive emergencies.

It does this through vasodilation, dilating the arteries and veins equally to lower both preload and afterload.

Side effects of nitroprusside include hypotension and headache. There is a risk of developing cyanide or thiocyanate poisoning.

For this reason, nitroprusside is only for short term use. The patient should have their blood pressure monitored continuously while receiving a nitroprusside infusion. The medication should not be mixed with any other medications in the IV line. Nitroprusside must be protected from light and used within 24 hours of being prepared. It is a light brown color, and should be discarded if it turns any other color.

Key Points

  • Nitroprusside
    • Clinical Use
      • Treats hypertensive emergencies
        • Also called hypertensive crisis or severe hypertension
    • Mechanism
      • Causes vasodilation
        • Equally dilates both arteries and veins
          • Lowers preload
            • Preload is the amount that the ventricles have to stretch at the end of diastole (when the ventricles are full of blood)
          • Lowers afterload
            • Afterload is the amount of resistance that the ventricle has to overcome to pump blood out to the body
    • Side Effects
      • Hypotension
      • Cyanide Poisoning
        • Nitroprusside is metabolized in the body to release cyanide ions, which can be toxic in high concentrations
        • Thiocyanate Poisoning
          • Thiocyanate is another byproduct of nitroprusside metabolism
      • Headache
    • Nursing Considerations
      • Protect from light
        • Nitroprusside is sensitive to light. Exposure can breakdown the drug and cause it to be ineffective
        • Keep medication and tubing covered and out of direct light
      • Use continuous blood pressure monitoring
        • Nitroprusside can drop blood pressure rapidly
      • For short term use only
        • Should not be used for longer than 3 days
        • Reduces the risk of cyanide poisoning
      • Do not mix
        • Nitroprusside must be given in its own infusion. Do not combine other medications into the same IV line as the nitroprusside.
      • Light brown solution
        • Nitroprusside is supposed to be a light brown color
        • Discard the solution if it is any other color (red, blue, green, etc.)
      • Discard after 24 hours
        • The solution is only good for 24 hours