my wife never smoked, drinks alcohol very little, but has had a nagging, chronic,intermittent cough for about 3 months. she has been to the doc, No sinus problems, had her chest x-rayed, given benzonatate, pardon the spelling, Proventil hfa 90 mcg inhaler..nothing helps. she is 72 years old and in very good health...but this cough is tough to deal with. RB