Are there any side effects to drinking alcohol?
I tried drinking from the Sparking Wine Fountain (which is an unlimited source of wine and can be drank multiple times) found in the Lady Boyle's Last Party mission, and can confirm that it does restore some of your health (and in that mission, it can also be used to fulfill an optional objective). This leads me to believe that alcoholic drinks are like any other food item in the game - they just restore some health.
I tried drinking it multiple times but have not noticed any negative side effects such as troubled vision or controls.
Looks like The Outsider has granted Corvo with a very useful power.