For fast, powerful multi-symptom relief: Use nondrowsy Dayquil for daytime relief and at night try Nyquil for fast relief so you can rest.. In each DayQuil Severe Cold & Flu LiquiCap, there are 325 milligrams of acetaminophen to relieve pain and reduce fever; 10 milligrams of dextromethorphan HBr to suppress coughs; 200 milligrams of guaifenesin to break up the congestion that causes coughs; and 5 milligrams of phenylephrine HCl to unclog nasal passages.. In each NyQuil Severe Cold & Flu LiquiCap, there are 325 milligrams of acetaminophen; 10 milligrams of dextromethorphan HBr; 6.25 milligrams of doxylamine succinate; and 10 milligrams of phenylephrine HCl.. Co-Pack contains 16 DayQuil LiquiCaps and eight NyQuil LiquiCaps..