A blood alcohol level is generally taken, which may not be provided to you.
An abnormal blood alcohol read on on a physician flags the patient as a potential alcoholic.
So, besides interfering with test readings, you end up with an comment in your health records that someday may come back to haunt you.
Well, if there is any fasting blood work involved, I would say yes, it should be avoided for at least 12 hours, other than that, I really do not think so, but I would just to be on the safe side.
Its not necessary but it could help