I would start by explaining a bit about Xanax. It is an short acting Benzodiazepine, which stays in the body for short periods.That is why you might need to take more than once when required.
All the Benzodiazepines(including Xanax) do have two worrying properties. 1. Tolerance, means body needs more dosage in the long term as body would get used to the dosage. 2. Dependence. It would be difficult to come off if the person is on this medication for long time.
Now what can be done. In most of the situations one need to come off benzodiazepines very gradually as otherwise the anxiety
nd withdrawal symptoms means the person might end back on the medication.
The way we usually recommend tapering off Xanax is to reduce slightly to by 0.25 mg every week.Once you have reached 1mg then you need to convert this to intermediate acting benzodiazepines like Diazepam as this can be helpful to deal with withdrawal symptoms in a slightly better way.
0.5 mg Xanax is equivalent to 10 mg Diazepam. So, when you get to 1mg Xanax then you might need to change to 10mg Diazepam twice daily. From here onwards you need to reduce by 2 mg every week(although some of my clients decided to reduce 5 mg every week to finish th process quickly). Usually reduce the day time dose first. So, once you moved to 10mg twice daily diazepam then you can reduce to 8 mg morning and 10 mg at night.Then further gradual reduction in a weeks time.
So, you have to do this very gradually.
In between if the anxiety is worsening please ask your Doctor to consider Vistaril 25 mg up to two or three times per day. This medication is not addictive and do need bit long time to develop tolerance .
I hope you find this information helpful.