Not Medical Advice: According to Drugs.com, taking DayQuil Severe Cold & Flu or DayQuil Cough with other drugs that make you sleepy or slow your breathing can worsen these effects. You should as your doctor before taking DayQUil with a muscle relaxer, sleeping pill, narcotic pain medicine, or medicine for anxiety, depression, or seizures.
See drugs that are known to interact with DayQuil Severe Cold & Flu and drugs that are known to interact with DayQuil Cough at Drugs.com.
DayQuil Severe Cold & Flu (acetaminophen, dextromethorphan, guaifenesin, and phenylephrine) is a combination medicine used to treat headache, fever, body aches, cough, chest congestion, stuffy nose, and sinus congestion caused by allergies, the common cold, or the flu.
Acetaminophen is a pain reliever and fever reducer.
Dextromethorphan is a cough suppressant. It affects the signals in the brain that trigger cough reflex.
Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making it easier to cough out through your mouth.
Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).
DayQuil Cough (dextromethorphan) is a cough suppressant. It affects the signals in the brain that trigger cough reflex.
Dextromethorphan is used to treat a cough. It will not treat a cough that is caused by smoking, asthma, or emphysema.
Check out Top 9 Ways to Prevent a Deadly Drug Interaction, shared by Drugs.com.