I usually can only take just one vicodin (7.5mg hydro), and if i mix it with anything else, it kills the vicodin buzz for me. Even one toke off some weed and the weed overpowers the vicodin.
If i take 2 7.5's (15mg), i feel good for a short time then i get all sweaty, feel like shit, feel like laying down. I have no opiate tolerance though, and i just may react to opiates wierd, because i dont really care much for the effect, a 7.5 vicodin will give me a very mild warm cozy feeling, but very subtle (like i said mixing any other drug seems to over power the vicodin buzz, just for me anyway) . If you have a script, just try one first, and see what that does, if you cant feel anything...maybe take another. I'd do that before trying to mix anything with it.. Just my opinion.