Coricidin is a drug that contains a combination of chlorpheniramine and acetaminophen, as stated by Drugs.com. It provides relief from sneezes, coughs, runny noses, hay fever and upper respiratory allergies, according to WebMD.
The chlorpheniramine in Coricidin is an antihistamine that reduces the effect of histamines in the body. Each tablet of Coricidin contains 4 milligrams of this antihistamine, according to the Coricidin HBP website. Acetaminophen, which is the other active ingredient, effectively reduces fever and relieves pain. Another ingredient is dextromethorphan hydrobromide, which is a nonnarcotic cough suppressant. This cough suppressant usually affects the cough center of the brain so that the patient can stop coughing.