I have a friend who is also on xanax for years,she drinks beer nightly with it,is this safe?

I think she take 1 mg. xanax 4 times a day and drinks about a six pack of beer a night. Lately she has been having other problems,dizzinesss,trouble concentrating,dry mouth. iw onder if it could be from the beer.She has drank beer with xanax for years,would it just mow do something to her.Her Pharmisist said its ok to drink beer