Nitroprusside (sodium)

What is this medication for?

• Hypertensive crisis (systolic >200 mmHg); acute/refractory CHF with fulminant pulmonary edema (esp. severe mitral regurgitation); cardiogenic shock (with dobutamine)
• Same — ICU-only use

How is it given?

This medication is normally given by your veterinary team (in clinic or hospital).

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Hypotension (excessively rapid BP reduction) (Main effect-related risk)
• Nausea, retching, restlessness, muscle twitching (Human-reported; resolve with rate reduction)

Worth a phone call to your veterinarian

• Cyanide toxicity (Prolonged infusion (>3 days), hepatic insufficiency, or depleted thiosulfate; early signs = metabolic acidosis, tolerance to therapy)
• Thiocyanate toxicity (Delirium (dogs); prolonged therapy + renal dysfunction)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Trouble breathing, collapse, seizures, severe vomiting or diarrhea, facial swelling, or pale gums

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Compensatory high blood pressure (AV shunts, aortic coarctation, Cushing's reflex); inadequate cerebral circulation
• has or has had: Hepatic insufficiency, severe renal impairment, hyponatremia, hypothyroidism; geriatrics more sensitive; less tolerance to hypovolemia/low red blood cell counts/blood loss during controlled low blood pressure
• has or has had: ICU-only drug — continuous BP monitoring and accurate flow-control pump essential

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • General anesthetics (halothane, enflurane)
  • Dobutamine
  • Other hypotensives (beta-blockers, ACE inhibitors)

Storage and handling

Reconstitute in D5W only; protect the bag from light (foil); discard if solution turns blue/dark red/green; stable 24 h after reconstitution; never add other drugs to the line; avoid extravasation. Administration set need not be protected.

Good to know

• Cyanide-toxicity antidote support: hydroxocobalamin (vitamin B12a) may prevent cyanogen toxicity; thiosulfate supplies sulfur for detoxification.
• Practical recipe (Plumb): 50 mg vial → 1000 mL D5W = 50 micrograms/mL; with a 60-drop/mL mini-drip set, 1 drop ≈ 0.83 micrograms.
• Typical course: stabilize ~12 h, wean nitroprusside over 6 h, start ACE inhibitor before/during taper — abrupt discontinuation without oral vasodilator backup risks rebound.
• The weaning sequence matters: nitroprusside first, then dobutamine, with enalapril layered in as infusions taper.