I've been smoking heroin on and off for the past day and took a .25 mg Xanax. How likely is it that my breathing becomes impaired? My tolerance to both drugs is high.
Just watch out that you don't get too disinhibited and start popping more Xanax. I overdosed on heroin 5 times in my using days, and benzos and H were responsible for 3 of them.
Those doses are safe, but be careful mixing benzos and opiates. That shit can easily become lethal and tolerance rapidly develops to both. I've known people who've died young mixing the two.