Antifibrotics
Oral drugs that slow scarring of the lung in idiopathic pulmonary fibrosis and other progressive fibrosing lung diseases. They slow decline; they do not cure.
What they are
Idiopathic pulmonary fibrosis (IPF) is a progressive scarring of the lung interstitium with no known cause. Two oral drugs are approved to slow the fall in lung function: nintedanib, a kinase inhibitor, and pirfenidone, a pyridone. Nintedanib is also used in other chronic fibrosing interstitial lung diseases that keep progressing and in the lung disease of systemic sclerosis. Neither drug reverses scar that is already there, so they are started early and continued while tolerated. Both are hard on the gut and the liver, and liver tests are checked regularly.
Mechanism of action
Repeated injury to the alveolar epithelium is thought to activate fibroblasts, which multiply, turn into myofibroblasts and lay down collagen. Growth factors such as PDGF, FGF and VEGF drive this response. Nintedanib blocks the intracellular kinase domain of their receptors, so fibroblasts proliferate and migrate less. Pirfenidone reduces fibroblast proliferation and fibrogenic growth factors in experimental models, but how it works in patients is not established.
Target: Fibroblast growth-factor signalling: PDGF, FGF and VEGF receptor kinases (nintedanib); not fully defined for pirfenidone
Drugs in this class
- NintedanibAn oral kinase inhibitor that slows lung scarring in idiopathic pulmonary fibrosis and other progressive fibrosing…Growth-factor receptor tyrosine kinases (VEGFR, FGFR and PDGFR)
- PirfenidoneAn oral antifibrotic for idiopathic pulmonary fibrosis; taken with food, it causes nausea, rash and sun sensitivity…Fibrogenic and inflammatory signalling in lung fibroblasts (molecular target not established)
Others in the class
- Lung transplantation is the only treatment that replaces a fibrotic lung
- Oxygen and pulmonary rehabilitation support patients alongside the drugs
Test yourself
Think of the answer, then tap the question to see it.
Which two oral drugs slow lung function decline in idiopathic pulmonary fibrosis?
Nintedanib and pirfenidone.
Which antifibrotic is classically linked with diarrhoea, and which with photosensitivity?
Nintedanib with diarrhoea; pirfenidone with photosensitivity and rash.
Which laboratory test is common to the monitoring of both antifibrotics?
Liver tests (ALT, AST and bilirubin).
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - NINTEDANIB capsule (DailyMed (U.S. National Library of Medicine), 2026); DailyMed - PIRFENIDONE- pirfenidone tablet, film coated (DailyMed (U.S. National Library of Medicine), 2025); Nintedanib: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026).
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Representative model, for educational purposes only.