Now, if you are taking Vicoden/Lortab(whatever) and/or regular tylenol or tylenol pm or any other drug with acetaminophen in it, it could get complicated. Normal healthy people are usually allowed to have only 4000mg of tylenol a day(to prevent liver damage). So if you have a headace and take 2 extra strengths, that burns up 1/4 of your total tylenol for the day. If your headache doesn't go away, and you take 1 or 2 lortabs, even more tylenol burned up for the day. If your liver is already damaged or you are elderly, you should only have 3000mg of tylenol a day. It can get kinda hard to keep it under the limit. That is part of the reason they came out with the lortab/vicoden that has the lower amount of acetaminophen.