expectoration
"Personally, taking 600mg. orally bid (or tid if symptomatic) for allergic bronchitis has reduced overall severity of seasonal exacerbations.

  Have recommended it to others with chronic sinus or respiratory conditions where it's indicated, and most of the time, reports are very favorable.

  A safe older drug that is largely neglected in the U.S.

  Recent trial in China showed decreased hospitalizations in persons with COPD who are maintained on N-acetylcysteine."