Gazoinks: Yes. Health potions heal physical wounds, drowning isn't really the sort of thing that could be healed by that.
Khadgar42: Sooo if a rapier pierced your lung and it's starting to collapse you drink a health potions and all your problems are solved?
How is that different from suffocating?
What happens when a Pit Fiend from the lower planes wants to eat your living heart and is ripping of your brest cage. I think quaffing a "full health restoration" potion solves the issue again, right?
I doubt it's as easy as you say.
Health potions are called "Health potions" for simplicity sake, actually, some/most of them are magically imbued with properties as tissue regeneration, so even if you get something critical pierced you can get it back into shape and its functions restored. The potion not only cleanses and regenerate damaged cells but it can also make them multiply at an accelerated rate to the former shape stored in evey individual DNA code.
And yes that´s in the second class of Wizardry Medicine : )
tinyE: Not to detract from the OPs intriguing query but I've always been more curious about taste, specifically mana. I can't imagine that something that color and consistency taste anything short of ass, and if it is nasty (as one would assume) how would one go about not puking it back up? Therein lies another question: if you drink a health or mana potion and the taste is so hideous that you immediately puke it up, does it take all the magic and or life with you when it comes flying out of your mouth onto the floor?
The trick is to lick it back before the ants get to it, the taste would have already changed substantially.
Fictionvision: You would drown, but if another party member can cast a resurrection spell on you, you should be fine.
Drinking all those potions probably keeps the characters up all night using the toilet though. So I'd imagine a few nights of no sleep from that would start to hurt their combat abilities.
tinyE: You see that's why I get on people who say a game like Postal 2 is stupid. The ability not only to piss but also have it effect your overall ability makes the game infinitely more realistic than a lot of the so called "good" shooters out there.
The again how would one go about taking a piss in that Halo suit?
Think......astronauts.