I have had a very deep cough off and on for 4 months. It produces very little phlegm, which is clear to light yellow in color. The cough was very bad, many times a day. Now I cough very hard for a few minutes a couple of times a day. It started in February and the doctor said it was probably a virus, but he gave me an antibiotic (Avelox) which did not provide any relief. I went back a couple of weeks later when the cough had not cleared up, and he said it probably was a virus in the beginning and now it was allergies. When I cough now, there is a strong metallic taste and a small amount of phlegm. In the last few days, t my chest is tight for short periods and when I breathe deeply, I cough.