Sodium nitroprusside

Sodium nitroprusside is indicated for the immediate reduction of blood pressure of adult and pediatric patients in hypertensive crises. Concomitant longer-acting antihypertensive medication should be administered so that the duration of treatment with sodium nitroprusside can be minimized. Sodium nitroprusside is also indicated for producing controlled hypotension in order to reduce bleeding during surgery. Sodium nitroprusside is also indicated for the treatment of acute congestive heart failure.

• Dilution to proper strength for infusion: Depending on the desired concentration, the solution containing 50 mg of sodium nitroprusside injection must be further diluted in 250 to 1000 mL of sterile 5% dextrose injection
• The diluted solution should be protected from light, using the supplied opaque sleeve, aluminum foil, or other opaque material
• It is not necessary to cover the infusion drip chamber or the tubing
• Verification of the chemical integrity of the product: Sodium nitroprusside solution can be inactivated by reactions with trace contaminants
• The products of these reactions are often blue, green, or red, much brighter than the faint brownish color of unreacted sodium nitroprusside injection
• Discolored solutions, or solutions in which particulate matter is visible, should not be used
• If properly protected from light, the freshly diluted solution is stable for 24 hours
• No other drugs should be administered in the same solution with sodium nitroprusside
• Avoidance of excessive hypotension: While the average effective rate in adult and pediatric patients is about 3 mcg/kg/min, some patients will become dangerously hypotensive when they receive sodium nitroprusside injection at this rate
• Infusion of sodium nitroprusside should therefore be started at a very low rate (0.3 mcg/kg/min), with upward titration every few minutes until the desired effect is achieved or the maximum recommended infusion rate (10 mcg/kg/min) has been reached. …

• Efficacy in the pediatric population was established based on adult trials and supported by the dose-ranging trial (Study 1) and an open label trial of at least 12 hour infusion at a rate that achieved adequate MAP control (Study 2) with pediatric patients on sodium nitroprusside
• No novel safety issues were seen in these studies
• In pediatric patients
• See CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION

• Sodium nitroprusside should not be used in the treatment of compensatory hypertension, where the primary hemodynamic lesion is aortic coarctation or arteriovenous shunting
• Sodium nitroprusside should not be used to produce hypotension during surgery in patients with known inadequate cerebral circulation, or in moribund patients (A.S.A. Class 5E) coming to emergency surgery. …

The hypotensive effect of sodium nitroprusside is augmented by that of most other hypotensive drugs, including ganglionic blocking agents, negative inotropic agents, and inhaled anesthetics.

(See also the boxed warning at the beginning of this insert.) The principal hazards of sodium nitroprusside injection administration are excessive hypotension and excessive accumulation of cyanide (see also OVERDOSAGE and DOSAGE AND ADMINISTRATION ). Excessive Hypotension: Small transient excesses in the infusion rate of sodium nitroprusside can result in excessive hypotension, sometimes to levels so low as to compromise the perfusion of vital organs. These hemodynamic changes may lead to a variety of associated symptoms; see ADVERSE REACTIONS . …

The most important adverse reactions to sodium nitroprusside are the avoidable ones of excessive hypotension and cyanide toxicity, described above under WARNINGS . The adverse reactions described in this section develop less rapidly and, as it happens, less commonly. Methemoglobinemia: As described in CLINICAL PHARMACOLOGY above, sodium nitroprusside infusions can cause sequestration of hemoglobin as methemoglobin. The back-conversion process is normally rapid, and clinically significant methemoglobinemia (>10%) is seen only rarely in patients receiving sodium nitroprusside injection. …

PREGNANCY Teratogenic effects: Pregnancy Category C. There are no adequate, well-controlled studies of sodium nitroprusside injection in either laboratory animals or pregnant women. It is not known whether sodium nitroprusside injection can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. Sodium nitroprusside injection should be given to a pregnant woman only if clearly needed. …

Overdosage of nitroprusside can be manifested as excessive hypotension or cyanide toxicity (see WARNINGS ) or as thiocyanate toxicity (see ADVERSE REACTIONS ). The acute intravenous mean lethal doses (LD50) of nitroprusside in rabbits, dogs, mice, and rats are 2.8, 5.0, 8.4, and 11.2 mg/kg, respectively. Treatment of cyanide toxicity: Cyanide levels can be measured by many laboratories, and blood-gas studies that can detect venous hyperoxemia or acidosis are widely available. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.