Codeine (codeine phosphate) contains the active ingredient codeine and is used to reduce pain from headache, the flu and common cold. See here for more information and to order.
A: Mucinex contains the active ingredient guaifenesin, which is an expectorant that helps loosen phlegm and thin bronchial secretions. Mucinex does not have rapid heart rate as a possible side effect. There is a product called Mucinex-D that contains pseudoephedrine, and this ingredient can increase heart rate.
Mucinex DM Overview. Updated: Mucinex DM is an over the counter medication used to control cough and loosen chest congestion in adults and children 12 years of age and older. It is a single product containing 2 ingredients: Guaifenesin and Dextromethorphan. Guaifenesin belongs to a group of drugs called expectorants.