Coricidin Cough and Cold contains dextromethorphan and chlorpheniramine maleate.
At the dosage used recreationally this is a bad combination, people have been injured and killed from taking enough coricidin to cause chlorpheniramine overdose.
Both of these drugs are metabolized by the same enzyme in your liver, with such high dosages of both substances your body may not be able to metabolize chlorpheniramine maleate quickly enough especially if you are one of ten caucasians who lack the enzyme.
http://www.coricidin.org/