I have come across the occasional can of beer/bottle of vodka. What will happen if I drink them? Can I get drunk?
Drinking an alcoholic drink will boosts your health above 100 - much like painkillers and hypostims, but with the added negative side effect of giving you blurred vision for a short period of time (the severity and duration of this effect vary depending on the drink).
The descriptions also imply that drinking them provides a "small increase in damage resistance", but I have no further information (such as duration or size of effect) and personally wonder if this is just indirectly referring to the fact you get a health boost.
If you examine the drink from your inventory it will tell you how much health it will add.