What is dextromethorphan, guaifenesin, and phenylephrine?
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). The combination of dextromethorphan, guaifenesin, and phenylephrine is used to treat stuffy nose, sinus congestion, cough, and chest congestion caused by the common cold or flu. Dextromethorphan, guaifenesin, and phenylephrine may also be used for other purposes not listed in this medication guide.
