How long do people stay drunk?

That depends on your gender, how fat you are, how much you had to drink, and how high your tolerance is for alcohol in your system. Most people will be sober in 30 - 36 hours after they have stopped drinking completely. (If you drank enough to stay drunk longer than that, you would probably suffer from acute alcohol poisoning.)

A high tolerance for alcohol, BTW, is one of the first signs of developing Alcoholism.