Alcohol means a lot of unnecessary calories, so not a good idea when cutting weight.
Also, the dehydrating effect means any training within a 48 hr period after a binge is hazardous because less fluid surrounding the brain and increased risk of concussions/knockouts. And in general, heavy drinking just drags down your cardio, athletic ability, balance and concentration.
Just keep it light. Cutting it out completely is best, but if you can't, then a couple a week won't hurt you.