depends on your opiate tolerance and benzo tolerance
If you have low tolerance to both then the combination could potentially be dangerous.
If you are used to taking 75 hydro then there's probably less of a problem.
generally, for someone with no tolerance to benzos. 0.5 or even 0.25 mg xanax is the starting dosage, so 0.75mg is 1.5 times that dosage.
long story short, tread lightly.