That'll certainly get "Impressive". Cough syrup will get you "Interesting". Although neither one is fatal, ordinary cold medicine with a few shots of liquor has a rather good chance of doing you in. Paracetamol, the usual active ingredient in things like Coldrex, is aggressively antagonistic with alcohol, and as alcohol has priority in being metabolized, will be shunted to an alternative metabolic route, which changes it into a highly toxic compound that royally fucks up your liver in a matter of hours.