Letter to the Editor: Consideration on "An evaluation of reports of ciprofloxacin, levofloxacin, and moxifloxacin- association neuropsychiatric toxicities, long-term disability, and aortic aneurysms/dissections disseminated by the Food and Drug Administration and the European Medicines Agency" by Bennett et al.

Introduction: Pulmonary fibrosis includes several lung disorders characterized by progressive fibrosis, of which idiopathic pulmonary fibrosis (IPF) is a particularly severe form with a median survival time of 3-5 years after diagnosis. Although numerous compounds have shown efficacy in attenuating pulmonary fibrosis using animal models, only a few compounds have shown their beneficial effects for IPF in clinical trials. Thus, there is an ongoing need to improve the preclinical development process to better identify, characterize and select clinically useful targets.Areas covered: In this review, we extensively describe current models of pulmonary fibrosis, focusing on rodent models, ex vivo models, and in vitro models.Expert opinion: Based upon our current understanding, improving the identification and characterization of clinically relevant molecules or pathways responsible for progressive fibrotic diseases and use of the robust preclinical model system to test these will be required to improve the drug development pipeline for pulmonary fibrosis. Combination of appropriate preclinical models with ex vivo (precision-cut lung slices) or in vitro models will benefit high-throughput drug discovery and validation of drug effects.