I have bronchitis. i feel a knot in my back when i breathe in, but can breathe ok. cough is not productive, with medicine. should i take my inhaler?

Inhaler: Without knowing what kind of inhaler you are referring to, it is difficult to give you a recommendation.

Yes: When people have chronic bronchitis, the bronchospasm may be felt even as muscle spasm. It also can come out as cough. Try to see if inhalers work. But also reconsider URI or allergic rhinitis as cause especially for a nonproductive cough, causing sinopulmonary syndrome. Discuss with your doctor to see what works best.