title: Ototoxicity of topical otomicrobial agents.
abstract: Topical antimicrobial solutions are used commonly for prevention or treatment of purulent otorrhea even though most solutions contain ototoxic agents. This study compares the cochlear and middle ear toxicity of cortisporin otic solution (COS), 0.3% gentamicin ophthalmic solution (GOS), benzalkonium chloride (0.026% and 0.05%), and 1.0% Ofloxacin, a new quinolone antibiotic. Saline 0.9% was used as a control. The agent was instilled daily for 7 days into the bulla of juvenile guinea pigs. The animals were sacrificed on the 14th day. The organ of Corti was examined using surface preparation light microscopy and scanning electron microscopy. The tympanic membrane (TM) and adjacent middle ear mucosa were examined with light microscopy. The average cochlear hair cell damage was 66% for COS, 6.5% for GOS, and 1% for Ofloxacin, benzalkonium and saline. COS and benzalkonium 0.05% produced moderate mucosal thickening and inflammation. However, this was not statistically different from the mild mucosal thickening produced by saline, GOS, Ofloxacin and 0.026% benzalkonium. There was statistically significant mild to moderate thickening of the TM for all agents compared to the saline control.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, University of Washington, Seattle, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Barlow
authors.forename: L G
authors.initials: LG
authors.lastname: Duckert
authors.forename: C S
authors.initials: CS
authors.lastname: Kreig
authors.forename: G A
authors.initials: GA
authors.lastname: Gates
mesh_terms: D000818:Animals; D001548:Benzalkonium Compounds / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use*; D002558:Cerebrospinal Fluid Otorrhea / Q000188:drug therapy* / Q000517:prevention & control; D003051:Cochlea / Q000187:drug effects*; D004338:Drug Combinations; D004432:Ear, Middle / Q000187:drug effects* / Q000648:ultrastructure; D005260:Female; D005839:Gentamicins / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use*; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000648:ultrastructure; D006854:Hydrocortisone / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D009355:Neomycin / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use*; D015242:Ofloxacin / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use*; D009925:Organ of Corti / Q000187:drug effects / Q000648:ultrastructure; D011112:Polymyxin B / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use*; D012965:Sodium Chloride / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use*; D014432:Tympanic Membrane / Q000187:drug effects
chemical_list: D001548:Benzalkonium Compounds; D004338:Drug Combinations; D005839:Gentamicins; C033225:hydrocortisone, neomycin, polymyxin B drug combination; D012965:Sodium Chloride; D015242:Ofloxacin; D009355:Neomycin; D011112:Polymyxin B; D006854:Hydrocortisone