Adult DM Maximum, Chest Congestion Relief DM, Children's Cough & Chest Congestion DM, Children's Daytime/Nighttime DM, Children's Delsym Cough + Chest Congestion DM, Children's Delsym Cough+ Day/Night, Children's Giltuss Cough & Chest Congestion, Children's Mucinex Cough, Children's Mucinex Cough & Mucus, Children's Mucus Relief Cough, Coricidin Mucinex and Mucinex DM both contain an expectorant that helps loosen mucus. Mucinex DM 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. . Adult DM Maximum, Chest Congestion Relief DM, Children's Cough & Chest Congestion DM, Children's Daytime/Nighttime DM, Children's Delsym Cough + Chest Congestion DM, Children's Delsym Cough+ Day/Night, Children's Giltuss Cough & Chest Congestion, Children's Mucinex Cough, Children's Mucinex Cough & Mucus, Children's Mucus Relief Cough, Coricidin 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 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 ).

what does the dm stand for in mucinex dm