The influence of fexofenadine hydrochloride (FEX; CAS 138452-21-8) on the production of eosinophil chemoattractants, RANTES and eotaxin, from nasal polyp fibroblasts (NPFs) was examined in vitro. Seventh to tenth generation NPFs were cultured with or without 1 microg/ml lipopolysaccharide (LPS) in the presence of various concentrations of FEX. After 24 h, the culture supernatants were obtained and assayed for eosinophil chemoattractants by enzyme-linked immunosorbent assay (ELISA). FEX at a dose of more than 250 ng/ml (but not 100 ng/ml) inhibited RANTES and eotaxin production in response to LPS stimulation, when the agent was added at starting of cell cultures. FEX also showed suppressive effect on RANTES and eotaxin production from NPFs after stimulation with tumor necrosis factor alpha (TNF-alpha). However, the addition of FEX at 12 h after culture could not inhibit factor production. The influence of FEX on messenger RNA (mRNA) expression in NPFs was then examined. The addition of FEX at 100 ng/ml scarcely affected the expression of RANTES and eotaxin mRNA. On the other hand, 250 ng/ ml of FEX significantly inhibited these mRNA expressions that were enhanced by LPS stimulation.