Pharmacologic class: Vasodilator
Therapeutic class: Antihypertensive
Pregnancy risk category C
FDA Box Warning
After reconstitution with appropriate diluent, drug isn't suitable for direct injection. Dilute reconstituted solution further in sterile 5% dextrose injection before infusing.
Drug may cause steep blood pressure decrease. In patients not properly monitored, this decrease can lead to irreversible ischemic injury or death. Give drug only when available equipment and personnel allow continuous blood pressure monitoring.
Except when used briefly or at low infusion rates, drug gives rise to significant amount of cyanide ion, which can reach toxic, potentially lethal levels. Infusion at maximum dosage rate should never last more than 10 minutes. If blood pressure isn't adequately controlled after 10 minutes of maximum-rate infusion, end infusion immediately. Monitor acid-base balance and venous oxygen concentration, but be aware that, although these tests may indicate cyanide toxicity, they provide imperfect guidance.
• Review these warnings thoroughly before giving drug.
Interferes with calcium influx and intracellular activation of calcium, causing peripheral vasodilation and direct blood pressure decrease
Injection: 50 mg/vial in 2 ml- and 5-ml vials
Indications and dosages
➣ Hypertensive emergencies; controlled hypotension during anesthesia
Adults and children: 0.3 to 10 mcg/kg/minute I.V., titrated to response
• Hepatic insufficiency
• Renal impairment
• Elderly patients
• Hypertension caused by aortic coarctation or atrioventricular shunting
• Acute heart failure caused by reduced peripheral vascular resistance
• Congenital (Leber's) optic atrophy, tobacco amblyopia
• Inadequate cerebral circulation
• Moribund patients
Use cautiously in:
• hepatic or renal disease, fluid and electrolyte imbalances, hypothyroidism
• elderly patients
• pregnant or breastfeeding patients
Be aware that nitroprusside is a high-alert drug.
Give only in settings with trained personnel and continuous blood pressure monitoring equipment.
• Dilute 50 mg in 2 to 3 ml of dextrose 5% in water (D5W); then dilute in 250 to 1,000 ml of D5W.
• Administer with microdrip regulator, infusion pump, or other device that allows precise flow rate measurement.
• Wrap infusion solution in aluminum foil or other opaque material to protect it from light.
CNS: increased intracranial pressure
CV: ECG changes, bradycardia, tachycardia, marked hypotension
Hematologic: decreased platelet aggregation, methemoglobinemia
Skin: rash, flushing
Other: pain, irritation, and venous streaking at injection site; too-rapid blood pressure decrease (causing apprehension, restlessness, palpitations, retrosternal discomfort, nausea, retching, abdominal pain, diaphoresis, headache, dizziness, muscle twitching); thiocynate or cyanide toxicity (initially, tinnitus, miosis, and hyper-reflexia) at blood level of 60 mg/L; severe cyanide toxicity (air hunger, confusion, lactic acidosis, death) at level of 200 mg/L
Drug-drug. Enflurane, ganglionic blockers, halothane, negative inotropic drugs, volatile liquid anesthetics: severe hypotension
Drug-diagnostic tests. Creatinine: increased level
Methemoglobin: hemoglobin sequestration as methemoglobin
Measure blood pressure frequently (preferably with continuous arterial line) to detect rapid drop.
• Monitor injection site closely to avoid extravasation. Use central line whenever possible. Ensure that infusion rate is precisely controlled to prevent too-rapid infusion.
• Obtain baseline ECG and monitor for changes.
Watch for signs and symptoms of cyanide toxicity (lactic acidosis, dyspnea, headache, vomiting, confusion, and loss of consciousness).
• Tell patient he'll be closely monitored during therapy.
Instruct patient to immediately report headache, nausea, or pain at injection site.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.