Background and Importance Interstitial lung diseases (ILD) is a group of rare diseases with bad prognosis, being Idiopathic pulmonary fibrosis (IPF) the most frequent of them. They can be treated with antifibrotic drugs: nintedanib or pirfenidone. However, these drugs have a high rate of adverse effects, which has a significant impact on treatment persistence.

Aim and Objectives To analyse the safety of pirfenidone and nintedanib in patients with ILD as well as treatment’s persistence, in a third-level hospital.

Material and Methods Retrospective observational study of patients with ILD treated with antifibrotic drugs from January 2016 to August 2022. Variables: sex, age, drug, duration of antifibrotic treatment, associated drug, switch to another antifibrotic drug, side effects, discontinuations, deaths. Information was collected from the hospital’s information systems.

Results 66 patients, 67% men, mean age 67 (47–86).

44 patients with nintedanib: 23 IPF, 14 progressive pulmonary fibrosis (PPF), 2 ILD associated with systemic sclerosis, 4 fibroemphysema and 1 ILD not classified. 5 of them were treated with an associated immunosuppressive drug: mycophenolate mofetil. 12 patients needed a dose reduction due to gastrointestinal effects: 100% diarrhea, 80% nausea. 1 patient needed temporary discontinuation due to increased transaminases, which were finally stabilised, being able to return to a higher dose. 2 patients needed discontinuation of treatment due to bleeding: 1 patient was on antiplatelet therapy and the other had a background of epistaxis. These two patients switched to pirfenidone.

22 patients with pirfenidone: all of them IPF. 2 patients needed dose reduction due to diarrhoea and 2 needed treatment discontinuation due to severe sunburns. These patients switched to nintedanib.

Persistence until progression 18 months with nintedanib and 24 months with pirfenidone. 8 patients died during treatment, 4 of them because of COVID-19 infection.

Conclusion and Relevance Thanks to a close follow-up in patients with ILD, it is possible to modify the dose and to achieve greater tolerance to treatments. The pandemic affected negatively during the year 2020, not only because of the impossibility of receiving medical appointments, but also due to the acceleration of their death. The rapid establishment of anti-fibrotic treatment and the adequate control of adverse effects are the key for this type of patients.

Conflict of Interest No conflict of interest