It is not a very good idea to combine Xanax along with alcohol. It can indeed be a deadly combination. Xanax is the CNS depressant and so is the alcohol. Both these can suppress the natural ability of the brain.
It can cause relaxing feeling in the brain. Similar is the function of alcohol. But combing both these can be highly lethal because they can depress CNS for the worse. Combined effects of alcohol with Xanax can create depressive mood as well as prevent a few body parts in functioning well. These body parts include brain, liver and kidney. Enough of mixture of these two substances can lead to shut down of any of these body parts.