As many people on this board know, I'm not in favor of popping pills. You're probably thinking about Diamox, but there are other pills to pop as well.
I live already at 4k feet so acclimation is not as much of a problem for me. In fact, it's not a problem at all for me. But that's me.
If you're coming up from sea level or thereabouts, perhaps Diamox or some other temporary remedy will work for you. There's no real way to find out. I'm sure I would get sick on McKinley, mainly from anxiety and being out of shape rather than altitude. I'm asthmatic and can't breathe most of the time anyway
All I can say is test yourself gradually. I drove my brother to the Ancient Bristlecones (10k ft) a couple years ago and he almost fell down and he lives next door...while I stood and watched him and waited for him to hurry up and quit being dizzy.
The following year, 2001, we hiked the Methuselah Trail in the Bristlecones without even a gasp of breath, but last summer he chickened out and would not climb Whitney with me so I gave the extra pass to someone else.
Well, hate to bend your eyes on this but I'm sure there are many people who would like to see me barf on the Sky Pilots. It's not gonna happen!
I was afraid of Whitney...I'm not any more. I would be afraid, however, if I had to climb the East Face to get there...I want my feet ON THE GROUND.
Vince