Will guifenesin or decongestants have an effect after thyroid removal surgery?

Patient: I had my thyroid removed in December. Prior to the removal my goiter would react every time I took guaifenesin. Now that the thyroid is gone is it safe to take Musinex which contains guaifenesin? I have chest congestion that I need to break up before it turns into bronchitis.

Doctor: I am not sure of the kind of reaction which occurred when you took guaifenesin before removal of your thyroid. However, I would advise against using any products containing guaifenesin as it is possible that you are allergic to the substance. There are other decongestants that you can use to relieve your symptoms such as those containing pseudoephedrine or ephedrine.