Dexamethasone has long been available as an injectable med. It is a steroid and can be given IV or IM. It can be almost a miracle drug in its fairly quick onset when injected IM into a person suffering from acute HAPE or HACE. (See examples as written by Jon Krakauer in "Into Thin Air" when they were trying to get Sandy Pittman and Beck Weathers off the mountain.) Points to remember are that it is for use in an emergency in these circumstances; it's not used to prevent AMS. And it's effects are temporary, as in a few hours. The only definitive intervention for a victim of HAPE or HACE is descent, as rapidly as possible.
