title: Benzalkonium chloride and nasal mucociliary clearance: a randomized, placebo-controlled, crossover, double-blind trial.
abstract: BACKGROUND
  Benzalkonium chloride (BKC) has been considered an innocuous preservative for prescription drugs.
  
  
  METHODS
  We performed a double-blind, placebo-controlled, randomized, crossover, single-center trial with a 3-week washout period in 43 healthy volunteers comparing the effect of 3-week use of saline nasal spray containing BKC 0.01% to preservative-free saline t.i.d. on nasal mucociliary clearance rate. Evaluations were done at the beginning and the end of each period by gamma-scintigraphy with technetium99m-labeled strontium.
  
  
  RESULTS
  Nasal mucociliary clearance rate was significantly impaired by BKC with a difference of 1.23 mm x min(-1) (p < 0.01) between periods.
  
  
  CONCLUSIONS
  BKC in the concentration used in nasal preparations impaired mucociliary clearance in healthy individuals after 3 weeks of use. Presently, when preservative-free alternatives are available, BKC could be a risk without benefit.
authors.affiliation: Research Center in Allergy and Immunology, Clinical Hospital, Federal University of Pernambuco, Recife, Brazil.
authors.forename: José Angelo
authors.initials: JA
authors.lastname: Rizzo
authors.forename: Décio
authors.initials: D
authors.lastname: Medeiros
authors.forename: Almerinda Rego
authors.initials: AR
authors.lastname: Silva
authors.forename: Emanuel
authors.initials: E
authors.lastname: Sarinho
mesh_terms: D000293:Adolescent; D000328:Adult; D001548:Benzalkonium Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009079:Mucociliary Clearance / Q000187:drug effects*; D011310:Preservatives, Pharmaceutical / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D001548:Benzalkonium Compounds; D011310:Preservatives, Pharmaceutical