For whatever it is worth, Dr. Peter Hacket at Telluride recommended for me that before I go to Whitney, I get a prescription from my doctor of Diamox, Dex and Zofran. Diamox was a preventative, and he said I could "try a short course of dexamethasone the first few days at altitude."
When I get altitude sickness, I see double vision and get lethargic, reserving all my energy for uncontrollable vomiting.
What I have found is my best preventative is spending 2-3 weekends sleeping at 10,000 in the weeks leading up to Whitney, and then a slow 3 day progression up Whitney--1 night at Outpost, 1 night at TC (with a hike that day if I feel up to it up to Trail Crest) and then the third day summit and descend.
