Dornase alfa is the generic designation of recombinant human deoxyribonuclease I,which acts by digesting extracellular DNA, released from dead neutrophils, that are present in increased amounts in Cystic Fibrosis sputum; this decreases the viscoelasticity of the sputum. Hence, it is one important drug used in Cystic fibrosis to make the sputum loose and less sticky, so that it can be coughed out from the lungs.
Dornase alfa has been shown to improve pulmonary function and to decrease the risk of respiratory tract infections that require parenteral antibiotics. By making the secretions loose, Dornase alfa prevents stasis of the mucus, which is an important factor leading to frequent chest infections.
The recommended dosage of Dornase alfa is 2.5 mg q12–24h inhaled via a jet nebulizer. Generally, it is well tolerated; however, reported adverse effects have included pharyngitis, laryngitis, voice alteration, rash, chest pain, and conjunctivitis. In a small proportion of patients, serum antibodies develop, but their clinical significance is unknown. These antibodies may have something to do with allergies that are sometimes reported with the use of Dornase alfa.
Dornase alfa cannot be mixed with other nebulized medications, because it reacts with other frequently used nebulisation drugs, which result in its denaturation.