The route of administration of amyl nitrite in “cyanide poisoning ” is
**Core Concept**
Amyl nitrite is a vasodilator used in the treatment of cyanide poisoning. It works by inducing methemoglobinemia, which binds to cyanide ions and forms cyanomethemoglobin, thereby reducing cyanide toxicity.
**Why the Correct Answer is Right**
The mechanism of amyl nitrite in treating cyanide poisoning involves the formation of methemoglobin. When amyl nitrite is inhaled, it is metabolized to nitric oxide (NO), which then reacts with guanylate cyclase to increase cyclic guanosine monophosphate (cGMP) levels. Elevated cGMP levels stimulate the production of methemoglobin, a form of hemoglobin that has a higher affinity for cyanide ions. This results in the formation of cyanomethemoglobin, which is less toxic than cyanide.
**Why Each Wrong Option is Incorrect**
**Option A:** Subcutaneous injection is not a recommended route of administration for amyl nitrite in cyanide poisoning.
**Option B:** Intravenous administration is not typically used for amyl nitrite in this context.
**Option C:** Oral administration is not effective for amyl nitrite in treating cyanide poisoning due to rapid metabolism and poor bioavailability.
**Clinical Pearl / High-Yield Fact**
Amyl nitrite is often used in conjunction with sodium thiosulfate, which helps to convert cyanide to thiocyanate, a less toxic compound. This combination is a key component of cyanide antidote kits.
**Correct Answer: C. Inhalation.