This is from http://www.freerepublic.com/focus/news/842004/posts?page=51#70
In New York, hospitals were placed on high alert based on government intelligence of a potential threat, naming cyanide as the specific terror agent.NYU Medical Center's Chief Medical Officer Eric Rackow wrote in a staff memo Wednesday that the hospital was taking all necessary precautions.
"NYU is working to ensure that we have adequate levels of the proper antidotes and pharmaceutical agents to treat patients should they be exposed to cyanide," Rackow wrote
As someone else pointed out, death from the gas is pretty quick, so I don't know how many drugs the hospital would stock.