Yes

Vasodilator

Management of hypertensive crises; congestive heart failure; used for controlled hypotension to reduce bleeding during surgery

C

Hypersensitivity to nitroprusside or any component; treatment of compensatory hypertension (aortic coarctation, arteriovenous shunting); high output failure; congenital optic atrophy or tobacco amblyopia

Except when used briefly or at low (<2 mcg/kg/minute) infusion rates, nitroprusside gives rise to large cyanide quantities. Do not use the maximum dose for more than 10 minutes. Use with extreme caution in patients with elevated intracranial pressure. Use extreme caution in patients with hepatic or renal dysfunction. Watch for cyanide toxicity in patients with impaired hepatic function. Use the lowest end of the dosage range with renal impairment. Thiocyanate toxicity occurs in patients with renal impairment or those on prolonged infusions. Continuous blood pressure monitoring is needed.

1% to 10%:

Central nervous system: Disorientation, psychosis, headache, restlessness

Endocrine & metabolic: Thyroid suppression

Gastrointestinal: Nausea, vomiting

Neuromuscular & skeletal: Weakness, muscle spasm

Otic: Tinnitus

Respiratory: Hypoxia

Miscellaneous: Sweating, thiocyanate toxicity

Symptoms of overdose include hypotension, vomiting, hyperventilation, tachycardia, muscular twitching, hypothyroidism, cyanide or thiocyanate toxicity. Thiocyanate toxicity includes psychosis, hyper-reflexia, confusion, weakness, tinnitus, seizures, and coma; cyanide toxicity includes acidosis (decreased HCO₃, decreased pH, increased lactate), increase in mixed venous blood oxygen tension, tachycardia, altered consciousness, coma, convulsions, and almond smell on breath.

Nitroprusside has been shown to release cyanide in vivo with hemoglobin. Cyanide toxicity does not usually occur because of the rapid uptake of cyanide by erythrocytes and its eventual incorporation into cyanocobalamin. However, prolonged administration of nitroprusside or its reduced elimination can lead to cyanide intoxication. In these situations, airway support with oxygen therapy is germane, followed closely with antidotal therapy of amyl nitrate perles, sodium nitrate 300 mg I.V. (6 mg/kg for children) and sodium thiosulfate 12.5 g I.V. (1.5 mL/kg for children); nitrates should not be administered to neonates and small children. Thiocyanate is dialyzable. May be mixed with sodium thiosulfate in I.V. to prevent cyanide toxicity.

None noted

Nitroprusside sodium should be reconstituted freshly by diluting 50 mg in 250-1000 mL of D₅W

Use only clear solutions; solutions of nitroprusside exhibit a color described as brownish, brown, brownish-pink, light orange, and straw. Solutions are highly sensitive to light. Exposure to light causes decomposition, resulting in a highly colored solution of orange, dark brown or blue. A blue color indicates almost complete degradation and breakdown to cyanide.

Solutions should be wrapped with aluminum foil or other opaque material to protect from light (do as soon as possible)

Stability of parenteral admixture at room temperature (25°C) and at refrigeration temperature (4°C): 24 hours

Causes peripheral vasodilation by direct action on venous and arteriolar smooth muscle, thus reducing peripheral resistance; will increase cardiac output by decreasing afterload; reduces aortal and left ventricular impedance

Onset of hypotensive effect: <2 minutes

Duration: Within 1-10 minutes following discontinuation of therapy, effects cease

Metabolism: Nitroprusside is converted to cyanide ions in the bloodstream; decomposes to prussic acid which in the presence of sulfur donor is converted to thiocyanate (liver and kidney rhodanase systems)

Half-life: Parent drug: <10 minutes; Thiocyanate: 2.7-7 days

Elimination: Thiocyanate renally eliminated

Administration requires the use of an infusion pump. Average dose: 5 mcg/kg/minute.

Adults: I.V. Initial: 0.3-0.5 mcg/kg/minute; increase in increments of 0.5 mcg/kg/minute, titrating to the desired hemodynamic effect or the appearance of headache or nausea; usual dose: 3 mcg/kg/minute; rarely need >4 mcg/kg/minute; maximum: 10 mcg/kg/minute. When administered by prolonged infusion faster than 2 mcg/kg/minute, cyanide is generated faster than an unaided patient can handle.

Blood pressure, heart rate; monitor for cyanide and thiocyanate toxicity; monitor acid-base status as acidosis can be the earliest sign of cyanide toxicity; monitor thiocyanate levels if requiring prolonged infusion (>3 days) or dose greater than or equal to 4 mcg/kg/minute or patient has renal dysfunction; monitor cyanide blood levels in patients with decreased hepatic function; cardiac monitor and blood pressure monitor required

Monitor thiocyanate levels if requiring prolonged infusion (>4 days) or greater than or equal to 4 mg/kg/minute; not to exceed 100 mg/mL (or 10 mg/dL) plasma thiocyanate

Therapeutic: 6-29 mg/mL

Toxic: 35-100 mg/mL

Fatal: >200 mg/mL

Cyanide: Normal <0.2 mg/mL; normal (smoker): <0.4 mg/mL

Toxic: >2 mg/mL

Potentially lethal: >3 mg/mL

Nitroprusside preparations must be wrapped with aluminum foil to protect from light in order to prevent breakdown of the parent drug to cyanide. A bluish tint to the solution indicates breakdown to cyanide. Thiocyanate levels should be monitored if high doses are used for more than 24 hours, particularly in patients with renal dysfunction and hepatic dysfunction. Nitroprusside is a very effective agent for controlled blood pressure lowering because of the very short half-life. Reasonably accurate titrations, based on target blood pressure can be achieved. Nitroprusside may also be useful for afterload reduction in patients with severe heart failure. Because of restricted cardiac output conditions, nitroprusside should be avoided in patients with aortic stenosis or coarctation. Nitroprusside should also be used cautiously in patients with acute myocardial infarction, because of hemodynamic effects and possible coronary steal.

May cause restlessness, disorientation, or psychosis

None reported, but monitor for hypotension if receiving a psychotropic

No information available to require special precautions

No effects or complications reported

Patient condition should indicate extent of education and instruction needed. This drug can only be given I.V. You will be monitored at all times during infusion. Promptly report any chest pain or pain/burning at site of infusion. Breast-feeding precautions: Consult prescriber if breast-feeding.

Brownish solution is usable, discard if bluish in color

Injection, as sodium: 10 mg/mL (5 mL); 25 mg/mL (2 mL)

Cohn JN and Burke LP, "Nitroprusside," Ann Intern Med, 1979, 91(5):752-7.

Harmon C and Wohlreich MM, "Sodium Nitroprusside-Induced Delirium," Psychosomatics, 1995, 36(1):83-5.

Palmer RF and Lasseter KC, "Drug Therapy: Sodium Nitroprusside," N Engl J Med, 1975, 292(6):294-7.

Schulz V, "Clinical Pharmacokinetics of Nitroprusside, Cyanide, Thiosulfate, and Thiocyanate," Clin Pharmacokinet, 1984, 9(3):239-51.

Vesey CJ and Cole PV, "Blood Cyanide and Thiocyanate Concentrations Produced by Long-Term Therapy With Sodium Nitroprusside," Br J Anaesth, 1985, 57(2):148-55.

Walters BN, "Urgent Treatment of Acute Hypertension," Br J Hosp Med, 1984, 31(1):49-52.

Wesson DE, Foley R, Sabatini S, et al, "Treatment of Acute Cyanide Intoxication With Hemodialysis," Am J Nephrol, 1985, 5(2):121-6.