What Should I Tell My Healthcare Provider Before Taking It?Prior to taking guaifenesin, talk to your healthcare provider if you have:
- Chronic obstructive pulmonary disease (COPD)
- Chronic bronchitis
- A cough that is accompanied by too much phlegm
- A fever, rash, or persistent headache
- A cough that lasts more than seven days or goes away and comes back
- Any allergies, including to food, dyes, or preservatives.
Also, let your healthcare provider know if you:
- Are a smoker
- Pregnant or thinking of becoming pregnant (see Guaifenesin and Pregnancy)
- Breastfeeding (see Guaifenesin and Breastfeeding).
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and nonprescription medicines, vitamins, and herbal supplements.
(Click Precautions and Warnings With Guaifenesin to learn more, including information on who should not take the drug.)
How Does Guaifenesin Work?Guaifenesin is part of a class of drugs called expectorants. It works by increasing the output of phlegm and bronchial secretions. This medicine thins out the phlegm and secretions, allowing them to be more easily "coughed up." Guaifenesin generally does not suppress coughing. Instead, it works to make the coughing more productive.
Guaifenesin is often marketed in combination products that include dextromethorphan, a cough suppressant. However, the logic of such a combination has been questioned, since the two ingredients have somewhat contradictory effects. Guaifenesin works to thin secretions and make coughing easier and more productive, but the dextromethorphan suppresses the cough.