Okay.. so I work in the field of psych. And yes, some drs absolutely DO prescribe xanax (or any benzos, for that matter) as a "standing dose". Quite often you'll just see it as a PRN dose.. like .5 mg qid (4 x per day) tid (3 x per day) or bid (2 x per day)
It all depends on how the person is presenting and who the dr is.
I have been to drs where they will not prescribe a benzo to you if you were lying on the floor in a full blown panic attack and others who treat a benzo as if it were lexapro. It's all variable.

And be very careful.. I deal with patients who are admitted into hospitals for all types of things, one of those things are when they are detoxing off of benzos.

you can have seizures, it is VERY serious.
consult w/ a dr asap.