The expanding armamentarium of drugs to aid sputum clearance: how should they be used to optimize care?

Abstract

Purpose of review: This review examines the evidence for use of agents that improve sputum clearance in cystic fibrosis.

Recent findings: The basic defect in cystic fibrosis causes abnormal airway surface liquid leading to mucus plugging and subsequent infection and inflammation in the airways. Agents that improve clearance of secretions should improve lung function, reduce infective exacerbations and may enhance survival. There are two main varieties of mucoactive therapy, namely mucolytic therapy, which reduces viscosity in order to improve clearance, and hyperosmolar therapy, which increases the airway surface liquid volume and increases mucociliary clearance. The development of mannitol as a hyperosmolar agent in dry powder form has heightened the debate regarding the optimal approach to sputum clearance. The evidence for use of individual agents is discussed, as well as a practical approach to combining therapies.

Summary: Dornase alfa, a mucolytic agent, and hypertonic saline and mannitol, both hyperosmolar agents, have all been shown to benefit patients with cystic fibrosis. The optimal combination of therapies has not been identified, but a combination of a hyperosmolar agent combined with a mucolytic provides the most logical approach to improving lung function and reducing exacerbations.