Sodium Nitroprusside

INDICATIONS AND USAGE 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 injection 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.

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.

Pregnancy: Teratogenic Effects: Pregnancy: Category C. There are no adequate, well-controlled studies of sodium nitroprusside in either laboratory animals or pregnant women. It is not known whether sodium nitroprusside can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. Sodium nitroprusside should be given to a pregnant woman only if clearly needed Nonteratogenic effects: In three studies in pregnant ewes, nitroprusside was shown to cross the placental barrier. Fetal cyanide levels were shown to be dose-related to maternal levels of nitroprusside.

BOXED WARNING Sodium Nitroprusside Injection is not suitable for direct injection. The solution must be further diluted in sterile 5% dextrose injection before infusion. Sodium nitroprusside can cause precipitous decreases in blood pressure (see DOSAGE AND ADMINISTRATION). In patients not properly monitored, these decreases can lead to irreversible ischemic injuries or death. WARNINGS (See also the boxed warning at the beginning of this insert.) The principal hazards of sodium nitroprusside 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 . CONTRAINDICATIONS 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.