I have had a sinus congestion problem for almost 2 weeks. been using mucinex (guaifenesin) dm. no runny nose. now extreme dry mouth the last two days. infection?

Mouth-breathing.: Since Mucinex (guaifenesin) dm does nothing on the nasal congestion, your dry mouth is likely from mouth-breathing. Try a nasal decongestant and see if this may help (mucinex (guaifenesin) d?) . If not, see your doctor to make sure that you don't have a sinus infection.

Mouth breathing: Most likely that your dry mouth is from the mouth breathing. If symptoms have been around for 2 weeks then it is worthwhile to see your doctor to see whether you have a sinus infection.