The lack of effect of benzalkonium chloride on the cilia of the nasal mucosa in patients with perennial allergic rhinitis: a combined functional, light, scanning and transmission electron microscopy study.
BACKGROUND: Controversy still exists about the effect of 0.02% benzalkonium chloride (BKC), a preservative in many nasal sprays, on human nasal epithelium in vivo. OBJECTIVE: To determine the safety of BKC by assessing its effect on the function and morphology of cilia of human nasal epithelium. METHODS: A single-centre, double-blind nasal biopsy study in 22 patients with perennial allergic rhinitis, receiving fluticasone propionate aqueous nasal spray (FPANS) containing BKC, BKC plus placebo or placebo alone for 6 weeks. Before, at two weekly intervals during treatment and 2 weeks after treatment ceased an indigocarmine saccharine transport time (ICST) was performed. RESULTS: ICST results did not significantly vary between the groups. There was no statistical relationship between the number of ciliated cells present and the treatment the patients received. Scanning and transmission electron microscopy examination showed no effects of BKC. CONCLUSION: Despite reports of its ciliostatic effects in vitro, BKC did not have such an effect when it was applied for 6 weeks (with/without fluticasone propionate) to the nasal mucosa of perennial allergic rhinitis patients in vivo.