It contains DXM. Drink the whole bottle and assuming you survive, you’ll get a similar high to PCP. If you’ve ever heard of the street drug “skittles,” that’s DXM. Cold medicine was popular with teens before the crackdowns because it was a lot easier to get cough syrup than illegal drugs. And that was one of the crackdowns that led to Seafoam being restricted, because once they couldn’t get their hands on cough syrup, they started looking for other things, like spray paint, which was also restricted and so now they do meth.
The whole thing is chasing a moving target and, really, just pushing teens into using much more dangerous drugs. Instead of just letting them eat pot brownies, now they’re out looking for meth and heroin. Seems dumb to me.