The overuse or underuse of dornase alfa.

The poor clearance of airway secretions in patients with cystic fibrosis perpetuates the chronic bronchopulmonary sepsis that is predominant. In recent years, novel drugs have been developed to alter the rheologic properties of the secretions in an attempt to improve airway clearance. Dornase alfa reduces the viscoelasticity of sputum from patients with cystic fibrosis and may enhance the clearance of secretions. Current clinical knowledge suggests that it is a safe treatment that improves pulmonary function and reduces respiratory exacerbations. The response, however, is heterogeneous and unpredictable. Scientific studies support the therapeutic rationale for the use of dornase alfa in that treatment reduces the viscoelasticity of airway secretions. Its effect on bacterial persistence and airway inflammation, however, is marginal. The key piece of information that would influence the long-term use of dornase alfa is how it affects disease progression, and at present this is unknown.