Mucolytics and supportive cystic fibrosis therapies

Treatments that thin airway mucus or replace missing digestive enzymes, the daily care that supports people with cystic fibrosis.

Updated Nov 1, 2026

What they are

A practical group of supportive treatments, most used in cystic fibrosis. Mucolytics thin airway secretions so they can be cleared: dornase alfa cuts the DNA that thickens infected sputum, acetylcysteine breaks the bonds between mucus proteins and hypertonic saline draws water into the airway. Pancreatic enzyme replacement (pancrelipase) is grouped here because it treats the other main problem of cystic fibrosis: the pancreas no longer delivers enough enzymes to digest food.

Mechanism of action

Thick mucus in cystic fibrosis comes from too little water on the airway surface plus large amounts of DNA and protein from inflammation. Dornase alfa is a deoxyribonuclease that cuts that DNA and lowers sputum viscosity. Acetylcysteine has a free thiol group that splits disulfide bonds in mucus glycoproteins. Pancrelipase supplies lipase, protease and amylase in the gut, where they digest fat, protein and starch that the patient's own pancreas can no longer handle.

Target: Extracellular DNA and mucus glycoproteins in airway secretions; dietary fat, protein and starch in the gut (pancrelipase)

Drugs in this class

Others in the class

Hypertonic saline (inhaled)
Carbocisteine
Bromhexine
Ambroxol

Test yourself

Think of the answer, then tap the question to see it.

What does dornase alfa break down in cystic fibrosis sputum?

Extracellular DNA, which makes infected sputum thick and sticky.

Why are most pancrelipase products enteric-coated?

Stomach acid quickly and permanently inactivates the enzymes; the coating releases them in the small intestine.

Which mucolytic is also an antidote, and for which poisoning?

Acetylcysteine, for paracetamol (acetaminophen) poisoning.

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