Nitroprusside Toxicity and Low-Dose Infusion

Excerpt

To the editor: Sodium nitroprusside is used extensively in the treatment of various cardiovascular emergencies. The toxicity profile of this drug requires frequent assessment of patients for signs of cyanide and thiocyanate toxicity, which may be elusive in view of concurrent diseases and medications. Prolonged infusions at doses well below the manufacturer's recommendations for maximum infusion rate, 10 µg/kg body weight ·min, are known to produce toxic accumulation of cyanide and thiocyanate (1, 2). We noted sodium nitroprusside toxicity at a dose rate that was 4 µg/kg · min or more for 14 hours, with a maximum rate of 4.9