title: Does topical application of 5-fluorouracil ointment influence inner ear function?
abstract: OBJECTIVE
  To investigate the effect of 5-fluorouracil (5-FU) ointment on the inner ear of guinea pigs.
  
  
  METHODS
  In group A (n = 7), 5-FU ointment was applied into the left external auditory canal. In group B (n = 10), 5-FU ointment was applied to the left middle ear through myringotomy. In both groups, the right ear served as a control. One week later the endocochlear DC potential (EP) was measured and morphology of the cochleae was examined using scanning electron microscopy (SEM) and light microscopy.
  
  
  RESULTS
  In group A, there was no significant difference between the EP values of the experimental side and the control side. In group B, there was a statistically significant difference between them (P < 0.05). Morphologic findings showed no damage.
  
  
  CONCLUSIONS
  5-FU ointment application to the external ear seems to be safe but its application to the middle ear may pose some risk of ototoxicity.
authors.affiliation: Division of Otorhinolaryngology, Department of Translational Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Japan.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Iwanaga
authors.forename: Fujinobu
authors.initials: F
authors.lastname: Tanaka
authors.forename: Naoki
authors.initials: N
authors.lastname: Tsukasaki
authors.forename: Mariko
authors.initials: M
authors.lastname: Terakado
authors.forename: Satoru
authors.initials: S
authors.lastname: Kaieda
authors.forename: Kenji
authors.initials: K
authors.lastname: Takasaki
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kumagami
authors.forename: Haruo
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000287:Administration, Topical; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage* / Q000633:toxicity*; D007758:Ear, Inner / Q000187:drug effects* / Q000502:physiology; D004594:Electrophysiology; D005072:Evoked Potentials, Auditory; D005472:Fluorouracil / Q000008:administration & dosage* / Q000633:toxicity*; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000187:drug effects; D008297:Male; D008855:Microscopy, Electron, Scanning; D009824:Ointments; D013316:Stria Vascularis / Q000187:drug effects
chemical_list: D000964:Antimetabolites, Antineoplastic; D009824:Ointments; D005472:Fluorouracil