Why not represent Drinking as a Disease condition track?
Each drink or maybe every 5 drinks cause an endurance check.
DC either starts at 5 +1 per drink, or 10 +1 per drink.
Failure means you drop one spot from the left to the right; going perhaps from:
Normal <--> Mildly drunk <--> Drunk <--> Badly Intoxicated <--> Alcohol Poisoning
Each negative step adds a -2 to all saving throws, attacks, and skill checks.
On Drunk you may not recall events of the evening the next morning if you fail and progress to Badly Intoxicated.
On Badly intoxicated you have the chance on a failure to pass out by failing the check by more than 10.
To start back up the ranks from right to left requires a full rest, and successful Endurance check. ( or at least 6 hours without drinking) New checks may be made once every 2 hours, or once every hour with an allies heal check. ( they can aid another to give bonus to the check) represented by aspirin, holding head over latrine for throwing up, etc...
Harder drinks may add additional penalty numbers to the DC.
Just a few thoughts.