A highly purified solution of recombinant human deoxyribonuclease I (rhDNAse) with selective DNA cleaving activity. Administrated through inhalation of the nebulized solution, dornase alpha catalyzes DNA degradation in viscous airway secretions, which may render airway secretions less viscous, thus promoting the clearing of airway mucous plugging and improvement in pulmonary function. or A drug given in an aerosol mist to decrease the thickness of mucus in the lungs of patients with cystic fibrosis. It is also being studied as a treatment to reduce the thickness of saliva in patients being treated for head and neck cancer. Dornase alfa inhalation solution contains an enzyme that breaks the DNA in mucus into small pieces and makes the mucus thinner. Also called Pulmozyme.