I am a waxer too, and the only thing is get it done a few days before you leave because the skin in that area is going to be red and irritated (bikini line in particular if you're doing that sort of thing) for a few days.
The only sort of reaction I've ever noticed with medications that I am on is if I get waxed while I am on high doses of steroids. That tends to make my skin thin out (?) a little bit and it just seemed to get a lot more irritated and heal up more slowly.
Waxing is awesome though, the hair won't even start peaking out for at least a week and a half or two. I love it, and I have a cerulogist who is awesome and fast and not weird at all about waxing between my ass cheeks!
Brazillian waxing FTW!!!!!!