This document discusses mucolytic drugs, which are used to thin mucus in the respiratory tract. It classifies common mucolytics - bromhexine, ambroxol, and acetylcysteine. It describes their mechanisms of action, dosages, and nursing responsibilities when administering them. Mucolytics work by breaking down mucus polymers to decrease viscosity and make mucus easier to cough up or suction out of the airways. Nurses should prepare for suctioning, encourage fluid intake, and maintain patients' airways when using mucolytics to treat respiratory disorders associated with excessive mucus production.