Pharmacology and the Nursing Process by Linda Lane Lilley: Practice Exam

Which substance is used in the treatment of cyanide toxicity from sodium nitroprusside?

1. Sodium thiosulfate

2. Calcium chloride

3. Magnesium sulfate

4. Potassium iodide

The correct answer is: Sodium thiosulfate

Sodium thiosulfate is the correct answer because it works as an antidote to the cyanide ions in sodium nitroprusside. This substance converts the cyanide to thiocyanate, which is less toxic and can be eliminated from the body through the kidneys. The other options, calcium chloride, magnesium sulfate, and potassium iodide, do not have any specific antidote properties for cyanide toxicity and therefore would not be effective in treating it. In fact, using calcium chloride or magnesium sulfate in high doses can actually worsen cyanide toxicity. Potassium iodide may also be ineffective and has potential side effects. Therefore, only sodium thiosulfate should be used in the treatment of cyanide toxicity from sodium nitroprusside.