Like about half of Asians, I suffer from the dreaded Asian Flush, which means that I lack a certain enzyme, aldehyde dehydrogenase2, causing me to have trouble breaking down acetaldehyde, a toxin that is a byproduct of the metabolism of alcohol yadda yadda yadda snooze snore bleh (click the wikipedia link, that's what it's there for.)
What that means is that, after a drink or two, I turn very red. (Once, when I was in Cancun, I had a beer with lunch. I was already flushed from the sun -- after the cervezas, I was purple.) Also, it means I am a cheap drunk, with the whole heart-pounding, head-spinning, got my drunk on going on.
Fortunately, there is a workaround -- a Pepcid AC antacid, taken shortly before (or even during) drinking, seems to counteraffect the flush. No one is really sure why -- the active ingredient is Famotidine, but anecdotal evidence seems to indicate that it works.
From personal experience, that is probably why I feel the effects of a few drinks more at home, when I don't take a Pepcid, than I do when I am out and about.
This is why you can usually find me with Pepcid (or the generic equivalent) in my glove compartment, keychain pill fob, jacket pocket, shaving kit and man-purse/laptop bag.