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 contains two key ingredients: dextromethorphan and guaifenesin. Dextromethorphan can cause you to get a false positive for Heroin, Opiates, Morphine on a drug test. Guaifenesin is an expectorant that helps thin and loosen mucus in the lungs, making it easier to cough up the mucus.