Dornase alfa

Cystic fibrosis is characterised by chronic bronchopulmonary sepsis. Various therapeutic modalities attempt to enhance the clearance of airway secretions. Dornase alfa (recombinant human deoxyribonuclease) reduces the viscoelasticity of sputum from patients with cystic fibrosis by depolymerising extracellular DNA. The drug is administered as an aerosol using a jet nebuliser at a dosage of 2.5mg once daily. It improves pulmonary function and reduces the risk of respiratory exacerbations requiring parenteral antibacterials. Various clinical trials have demonstrated a heterogeneous response to dornase alfa and have been unable to predict which groups of patients benefit from treatment. Patient selection is further complicated because some individuals do not exhibit improvements in lung function, but benefit in terms of a decrease in infective exacerbations. All patients with cystic fibrosis who produce purulent sputum are potential candidates for dornase alfa therapy. We suggest that compliant patients be considered for treatment with dornase alfa, irrespective of disease severity, but should be closely monitored and be assessed at regular intervals to monitor treatment response.