What is Mucinex DM? Dextromethorphan is a cough suppressant. Guaifenesin is an expectorant. Mucinex DM is a combination medicine used to treat cough and chest congestion caused by the common cold or allergies. Dextromethorphan will not treat a cough that is caused by smoking.
Fact Checked Mucinex DM is an over-the-counter (OTC) combination medication that relieves cough and chest congestion caused by the common cold, flu, and allergies. Each tablet combines dextromethorphan hydrobromide, a cough suppressant, with guaifenesin, a drug that loosens mucus and bronchial secretions in the lungs.
Official answer by Drugs.com Mucinex D is (guaifenesin and pseudoephedrine) is an expectorant/nasal decongestant combination, and Mucinex DM (guaifenesin and dextromethorphan) is an expectorant/cough suppressant combination. Mucinex D and Mucinex DM both contain the expectorant guaifenesin (which is contained as a single ingredient in Mucinex ). Generic Name (S): dextromethorphan-guaifenesin Uses This combination medication is used to relieve coughs caused by the common cold, bronchitis, and other breathing illnesses. Guaifenesin belongs ruwHSdp.