sodium nitroprusside in 0.9% sodium chloride

WARNING: (A) EXCESSIVE HYPOTENSION; (B) CYANIDE TOXICITY (A) EXCESSIVE HYPOTENSION: Sodium nitroprusside can cause precipitous decreases in blood pressure which can lead to irreversible ischemic injuries or death. Use only with continuous blood pressure monitoring [see Dosage and Administration ( 2.2 ) and Warnings and Precautions ( 5.1 ) ] . (B) CYANIDE TOXICITY: Sodium nitroprusside metabolism produces dose-related cyanide, which can be lethal. A patient’s ability to buffer cyanide will be exceeded in less than one hour at the maximum dose rate (10 mcg/kg/min); limit infusion at the maximum rate to as short a duration as possible [see Warnings and Precautions ( 5.2 ) ] . WARNING: (A) EXCESSIVE HYPOTENSION; (B) CYANIDE TOXICITY See full prescribing information for complete boxed warning. (A) Sodium Nitroprusside can cause precipitous decreases in blood pressure which can lead to irreversible ischemic injuries or death. Use only with continuous blood pressure monitoring. ( 2.2 , 5.1 ) (B) Sodium nitroprusside metabolism produces dose-related cyanide, which can be lethal. A patient’s ability to buffer cyanide will be exceeded in less than one hour at the maximum dose rate (10 mcg/kg/min); limit infusion at the maximum rate to as short a duration as possible ( 5.2 ).

5 WARNINGS AND PRECAUTIONS Thiocynate toxicity ( 5.3 ) Methemoglobinemia ( 5.4 ) Increases in intracranial pressure ( 5.5 ) Diminished capacity to compensate for anemia and hypovolemia with anesthesia during surgery ( 5.6 ) 5.1 Excessive Hypotension Sodium nitroprusside, can cause excessive hypotension leading to hypoperfusion of vital organs. Hypotension should resolve within 1-10 minutes after discontinuation of the nitroprusside infusion; during these few minutes, it may be helpful to put the patient into a head-down (Trendelenburg) position to maximize venous return. If hypotension persists more than a few minutes after discontinuation, consider other causes. Elderly patients may be more sensitive to the hypotensive effects of the drug. 5.2 Cyanide Toxicity Sodium nitroprusside infusions above 2 mcg/kg/min generate cyanide ion (CN¯) faster than the body can normally dispose of it. At the maximum recommended infusion rate of 10 mcg/kg/min, the patient’s ability to buffer CN¯ will be exceeded in less than one hour [see Overdose ( 10 )] . Patients with hepatic dysfunction are more susceptible to cyanide toxicity. An early manifestation of cyanide toxicity is increasing dosage requirements to maintain blood pressure control. Metabolic acidosis may not be evident for more than an hour after toxic cyanide levels accumulate. If cyanide toxicity develops, discontinue sodium nitroprusside, and consider specific treatment of cyanide toxicity [see Overdosage ( 10 )]. 5.3 Thiocyanate Toxicity Most of the cyanide produced during metabolism of sodium nitroprusside is eliminated in the form of thiocyanate. Thiocyanate is mildly neurotoxic (tinnitus, miosis, hyperreflexia) at serum levels of 1 mmol/L (60 mg/L). Thiocyanate is life-threatening when levels reach ~200 mg/L. Therefore, routine monitoring of plasma thiocyanate levels is recommended in patients with normal renal function when cumulative sodium nitroprusside doses exceed 7 mg/kg/day. In patients with eGFR <30 mL/min/1.73 m 2 , limit the mean infusion rate to less than 3 mcg/kg/min. In anuric patients, limit the mean infusion rate to 1 mcg/kg/min. Renal hemodialysis may be used to eliminate thiocyanate in cases of severe toxicity. 5.4 Methemoglobinemia Sodium nitroprusside infusions cause conversion of hemoglobin to methemoglobin in a dose- dependent manner. Methemoglobin binds oxygen more strongly than does hemoglobin, and when methemoglobin levels are elevated, oxygen release from red blood cells in tissue capillaries may be impaired. However, conversion of methemoglobin back to hemoglobin is normally rapid, and clinically significant methemoglobinemia is infrequent. Suspect methemoglobinemia in patients who have received >10 mg/kg of sodium nitroprusside and who exhibit signs of impaired oxygen delivery despite adequate cardiac output and adequate arterial pO2. Methemoglobinemic blood is chocolate brown, without the expected color change on exposure to air. Methemoglobin levels >10% are considered clinically significant. When methemoglobinemia is diagnosed, the treatment of choice is 1-2 mg/kg of methylene blue, administered intravenously over several minutes. 5.5 Increased Intracranial Pressure Like other vasodilators, sodium nitroprusside can cause increases in intracranial pressure. 5.6 Anemia and Hypovolemia with Anesthesia When sodium nitroprusside (or any other vasodilator) is used for controlled hypotension during anesthesia, the patient’s capacity to compensate for anemia and hypovolemia may be diminished. If possible, correct pre-existing anemia and hypovolemia prior to administration.

6 ADVERSE REACTIONS The following adverse reactions are described, or described in greater detail, in other sections: Hypotension [see Warnings and Precautions ( 5.1 )] Cyanide Toxicity [see Warnings and Precautions ( 5.2 )] Thiocyanate Toxicity [see Warnings and Precautions ( 5.3 )] Methemoglobinemia [see Warnings and Precautions ( 5.4 )] Increased Intracranial Pressure [see Warnings and Precautions ( 5.5 )] Anemia and Hypovolemia [see Warnings and Precautions ( 5.6 )] Less common adverse reactions include: Cardiovascular: Bradycardia, electrocardiographic changes, tachycardia, palpitations, retrosternal discomfort Dermatologic: Rash Endocrine: Hypothyroidism Gastrointestinal: Ileus, nausea, abdominal pain Hematologic: Decreased platelet aggregation Musculoskeletal: Muscle twitching Neurologic: Increased intracranial pressure, dizziness, headache Miscellaneous: Flushing, diaphoresis, venous streaking, irritation at the infusion site Most common adverse reactions are hypotension and cyanide toxicity ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Slate Run Pharmaceuticals, LLC at 1-888-341-9214 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.