Which of the following drugs has been used in the treatment of angina by inhalation and has a very rapid onset and brief duration of action?

Amyl nitrite is given by inhalational route and used in cyanide poisoning. The inhalation route provides very rapid absorption and, like the sublingual route, avoids the hepatic first-pass effect. Because of its unpleasant odor and extremely sho duration of action, amyl nitrite is now obsolete for angina. Amyl nitrite is a highly volatile liquid. It is available in fragile glass ampules packaged in a protective cloth covering.Ampule has to be crushed with fingers, and the vapors have to be inhaled through protective covering. This antidote for cyanide poisoning is Hydroxocobalamin (IV) , a form of vitamin B12, which also has a very high affinity for cyanide and combines with it to generate another form of vitamin B12.