The most noticable difference is your visuals will be muted. other differences may be more subtle. the emotional content may be more likely to be negative. those who are into entity/spirit contact claim those dudes are less likely to hang around for you when you're drunk.
My roomate likes to have alchohol in his system when he does Salvia. I agree with Pepostico, I noticed it effects you when drunk, but when totally sober, Salvia can chew you up and spit you out. . . .
Wierd, I was just wondering the same thing and next thing you know I open the forum and it is the first topic. LOL