Benzalkonium chloride as a preservative in nasal solutions: re-examining the data

Recent studies have suggested that benzalkonium chloride (BKC), an antimicr obial agent used as a preservative in nasal sprays, lacks deleterious effec ts on the nasal ciliated epithelium. Other data, including recent in vivo f indings, suggest that BKC may, in fact, produce adverse clinical effects on human nasal tissue, including the aggravation of rhinitis medicamentosa. T oxic effects have also been reported. In light of the discrepancy between n egative results and studies suggesting no safety concerns, we consider the possibility of problems in the design and methodology of some of the studie s and in the interpretation of results, Clearly, further research is warran ted to clarify the significance of conflicting findings. In the meantime, w ithout conclusive data regarding BKC and the possibility of harmful effects , the use of nasal formulations without BKC might be a reasonable alternati ve. (C) 2001 Harcourt Publishers Ltd.