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.
Is Mucinex (guaifenesin) safe during pregnancy? Mucinex (generic name guaifenesin) is an oral cough, cold, sinus and allergy medication, expectorant and decongestant usually considered safe in the second and third trimesters. However, the over-the-counter drug should be avoided in the first trimester due to potential risks to the growing fetus [1].