let me tell you man, from personally experience.
Whe you mix an opiate and a benzo it seems to amplify the downing effects by 10.
One night i took 35 mg oxy and 2 mgs of xanax.
The oxy on itself would have just had me with an alright buzz, feelin good.
The xanax on itsself would have had me pretty inhibition free and just chill.
This was the first time i had ever mixed the two and let me tell you i was Messed up. The xanax took away the high of the oxy completely and i ended up staying awake for about 1 1/2 hours then passing out.
IMO i would use then at different times, or maybe just limit the xanax with the mixture.
Maybe just save the xanax and take a higher dose of Oxy if your used to it.
And i feel since this is a harm reduction site i should warn you, both of these dugs are CNS depressants. It is a bad idea to mix two depressant. Its not just a ba idea, it can be dangerous.