“Coffee does not help you get sober. If you’re plastered, you’re going to have to wait several hours for the alcohol to leave your system on its own. Drinking coffee won’t make your body metabolize alcohol faster.  However, coffee can affect your drunken state by tricking your mind into thinking you’re close to sobriety. It turns out the caffeine in coffee is a stimulant, which can make you feel like you’re ready to handle certain potentially dangerous activities — like driving.”

Discovery.com