Welcome to the board. This post is not a good basis for a wiki article, so I'm moving it to basic drug discussion. I suggest you read the posting guidelines of the subforum you're in prior to posting.
The short answer is that the naloxone will reverse heroin's effects but will leave the xanax unaffected.
I had read the posting guidelines and have been viewing bl for years now, I just could not find the drug discussion on the mobile bl at the time of the post, sorry about that..