Just to add a small point of information. I suggest consumers, which is all of us, read the CDC recommendation on what diagnoses do and do NOT require an antibiotic. You will likely be surprised to learn that for almost all patients no antibiotic should be given for either bronchitis nor sinusitis.
CDC - Get Smart: Acute Bronchitis (Chest Cold)
CDC - Get Smart: Sinus Infection (Sinusitis)
And never needed when the diagnosis is viral upper respiratory infection also known as a cold. Doctors may write an antibiotic when it is not needed to keep you happy if it seems you expect one. Speak up, tell the doctor you only want a medication if it is clearly needed. This approach will lower your medication cost to zero sometimes.