Which medication regimen is used to facilitate airway clearance in a child with cystic fibrosis?

• A. Ibuprofen and azithromycin
• B. Ivacaftor
• C. Prophylactic clindamycin
• D. Inhaled dornase alfa

Answer: (D)

Inhaled dornase alfa is used to facilitate airway clearance because it directly thins the thick, sticky mucus characteristic of cystic fibrosis. It is a DNase enzyme that breaks down extracellular DNA released by neutrophils into sputum, lowering mucus viscosity and making it easier to cough up or clear with chest physiotherapy. This mucolytic effect improves mucus clearance and lung function, reducing the frequency of exacerbations when used as part of an airway clearance regimen in children with CF. Other options don’t primarily aid mucus clearance: anti-inflammatory or CFTR-modulating agents help other aspects of disease, and prophylactic antibiotics target bacteria rather than mucus production or clearance.