How many hours one can get an atarax or Xanax (alprazolam) after having drunk?

Alcohol and sedative. I would wait 24 hours to be completely safe since xanax (alprazolam) can be deadly if mixed with or without alcohol. Atarax is a very sedating antihistamine which can have very serious reactions as well. You really should ask your pharmacist as well as your primary doctor who prescribed since doses also make a difference.