Effect of p-aminopropiophenone (PAPP), a cyanide antidote, on cyanide given by intravenous infusion.

Beagle bitches were infused with potassium cyanide solution after protection with p-aminopropiophenone (PAPP). Methaemoglobin levels fell very rapidly after the start of the infusion. Whole blood and plasma cyanide estimations revealed that most of the cyanide was sequestered inside the red cells. Animals survived a supralethal dose of cyanide when protected with PAPP.