There are 2 opiates in Vicodin, Thebaine and Codeine. Codeine is the weakest of opiates, and thebaine acts in the same way as both morphine and codein. I can't imagine Thebaine being in a cough medicine though, as Vicodin and Thebaine both are schedule 3 substances. If it's only codein, there's really no sense relating it to Vicodin (A very powerful and adictive opioid analgesic).

I wouldn't recommend smoking while your mouth is healing as it could really mess up the whole healing process. I'm sure somebody more knowledgeable (IE Birdgirl) could tell you more. I just wouldn't recommend it. If you really must indulge, it would be much better to vaporize. If you can't do that, try making a weed smoothy. You'd need some sort of fat or alcohol in it for it to absorb properly though.