Vicks NyQuil Severe Cold & Flu is a maximum-strength, over-the-counter medication designed to relieve nine major symptoms. It is effective against cough, congestion, fever, sore throat and pain. It contains acetaminophen (pain reliever), dextromethorphan (cough suppressant), doxylamine succinate (antihistamine), and phenylephrine (decongestant) to aid sleep while sick. Follow directions for recommended dosage.