Are you taking an ACE inhibitor or Beta blocker for anything? My husband had a two year cough with sinus drainage and the same physician who prescribed his blood pressure med just kept prescribing him antibiotics for his "sinus infections". Until we did some investigating on our own and discovered it was from his Bp meds. He stopped taking them (with his dr's approval) and within 3 weeks no more cough or drainage. He was vomiting with the coughing spells they were so bad. Because he had sinus drainage his doc thought it coudn't be med related. But we found a forum where many had his exact symptoms of cough with drainage who were on his type of med. You never know. The more I live the more I see how we are the ones in charge of our own dx/cures sometimes.