title: Oxymetazoline solutions inhibit middle ear pathogens and are not ototoxic.
abstract: OBJECTIVE
  This study was performed to explore the antimicrobial activity of two commercially available oxymetazoline hydrochloride preparations against the common pathogens of otitis media and to demonstrate the lack of ototoxicity of these agents and of United States Pharmacopeia (USP) oxymetazoline in a standard animal model.
  
  
  METHODS
  Disc diffusion assays and minimum inhibitory concentration studies against American Type Culture Collection reference strains of common middle ear pathogens were used to evaluate the antimicrobial activity of oxymetazoline solutions and fluoroquinolone drops, and outer hair cell counts were performed on scanning electron micrographs of guinea pig basal cochlear segments after chronic exposure to oxymetazoline solutions and positive and negative controls.
  
  
  RESULTS
  Oxymetazoline nasal spray and eyedrops had activity against all species tested except Haemophilus influenzae and Pseudomonas aeruginosa. The USP oxymetazoline had limited antimicrobial activity. Oxymetazoline nasal spray, oxymetazoline eyedrops, and USP oxymetazoline had ototoxicity profiles indistinguishable from that of the saline solution control.
  
  
  CONCLUSIONS
  Commercially available oxymetazoline solutions are active against several of the common pathogens of otitis media. This antimicrobial activity is not due to oxymetazoline, and is more likely due to preservatives present in the solutions. The solutions tested are not ototoxic to guinea pig outer hair cells. Oxymetazoline solutions are potential substitutes for broad-spectrum antibiotic drops after tympanostomy tube placement.
authors.affiliation: Dept of Otolaryngology-Head and Neck Surgery, Temple University School of Medicine, 3400 North Broad St, Philadelphia, PA 19140, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Isaacson
authors.forename: Bettina A
authors.initials: BA
authors.lastname: Buttaro
authors.forename: Valorie
authors.initials: V
authors.lastname: Mazeffa
authors.forename: Geming
authors.initials: G
authors.lastname: Li
authors.forename: Dorothy A
authors.initials: DA
authors.lastname: Frenz
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology*; D000336:Aerosols; D000818:Animals; D001419:Bacteria / Q000187:drug effects*; D002452:Cell Count; D003051:Cochlea / Q000187:drug effects / Q000648:ultrastructure; D004432:Ear, Middle / Q000187:drug effects* / Q000382:microbiology*; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D009883:Ophthalmic Solutions; D010109:Oxymetazoline / Q000008:administration & dosage / Q000009:adverse effects* / Q000494:pharmacology*; D011310:Preservatives, Pharmaceutical / Q000494:pharmacology; D012996:Solutions
chemical_list: D000316:Adrenergic alpha-Agonists; D000336:Aerosols; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical; D012996:Solutions; D010109:Oxymetazoline