I had been prescribed Diamox a few weeks before the Whitney hike. I tested it at home and felt comfortable with they way it would work best for me, minus the side effects people complain of. We had been training on Mt Shasta and I had not had issues with altitude, nor at the Mono Pass area where we did an acclimation hike before Whitney. I did not use Diamox then nor did I use it for the Whitney hike. I only had it with me as it is my understanding that it may possibly help symptoms but definitely not cure them on the mountain. Some of the hikers who assisted us down actually had Diamox with them as well but there was no point in taking it at that time.