Thick chest mucus. Dornase alfa, called pulmozyme, (dornase alfa) is a medicine that makes lung mucus thinner and easier to cough up. It was developed for patients with cystic fibrosis and is used every day for months or years. It is not used for short-term colds or bronchitis. It gets into the lungs by breathing in a mist of the medicine from a nebulizer machine. Treatments usually take 10-20 minutes.