Other mucoactive agents for cystic fibrosis.

This review examines specific mucoactive agents from three classes: expectorants, which add water to the airway; ion-transport modifiers, which promote ion and water transport across the epithelium of the airway; and mucokinetics, which improve cough-mediated clearance by increasing airflow or reducing sputum adhesivity. The agents are isotonic and hypertonic saline, mannitol, denufosol and beta-agonists. Our understanding of these agents has recently improved through pre-clinical research, clinical trials and, in particular, extensive research into the nature of the liquid lining the surface of the airway, both in health and in cystic fibrosis (CF). For each agent, recent research is reviewed, highlighting the evidence for possible mechanisms of action and for clinical efficacy in CF, as well as the implications for the optimal clinical application of the agent.