Diffuse lung diseases ascribed to drugs: a nationwide observational study over 37 years using the French pharmacovigilance database.

Background: Drug-induced interstitial lung disease (DI-ILD) is a heterogeneous subgroup of interstitial lung diseases (ILD). The number of molecules involved is increasing with time. Due to their low incidence, DI-ILDs may be detected only after a drug has been marketed, notably through Adverse Drug Reaction (ADR) reports to pharmacovigilance centres. The aim of our study was to describe drug-induced diffuse lung disease cases notified to and recorded by the French Pharmacovigilance Database (FPVD), reported clinical pictures and the potentially causal drugs.

Methods: This retrospective study included cases registered in the FPVD from 1st January 1985 to 1st April 2022 which had ADR coded in MedDRA with a High Level Group Term "Lower respiratory tract disorders (excluding obstruction and infection)" involving patients aged 18 and over.

Results: We analysed 7234 cases involving 13 059 suspect medications and 1112 specific molecules. Cases were categorised as serious in 96.7% and in 13.3% death ensued. Men accounted for 54.4% of the cases. Median age was 69 [18-103] years. The most prevalent ADRs were "ILD" (51.0%), "Pulmonary oedema" (acute/non-acute) (15.6%) and "Pulmonary fibrosis" (10.5%). "Anti-cancer drugs" (31.2%) and "Cardiovascular drugs" (29.1%) were the most prominent therapeutic classes involved, with amiodarone being the most commonly reported suspected drug (10.0%), followed by methotrexate (3.1%).

Conclusion: This study from a large nationwide dataset spanning 37 years is the largest known to date. Drug-induced diffuse lung diseases are serious with a potentially fatal outcome. Accurate diagnoses remain essential to identify it properly and discontinue the culprit drug urgently.