Ototoxic effect of daptomycin applied to the guinea pig middle ear

Hidetoshi Oshima, Kazuhiro Nomura, Muneharu Yamazaki, Jun Suzuki, Tetsuaki Kawase, Toshimitsu Kobayashi, Yukio Katori

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Conclusion: Daptomycin applied topically at a concentration of 50 mg/ml caused mild but statistically significant hearing impairment. Outer hair cells were not damaged by daptomycin. Great care must be taken when there is a chance that daptomycin can reach the middle ear. Objective: Ototopic antibiotic eardrops are frequently used to treat external and middle ear infections. Daptomycin is a new anti-methicillin-resistant Staphylococccus aureus (MRSA) drug with unknown ototoxicity. The current study examined the ototoxic effect of daptomycin in topical applications to guinea pig ears. Methods: Twenty-three male Hartley guinea pigs (weight, 250-640 g) were divided into three groups receiving daptomycin (50 mg/ml), gentamicin (50 mg/ml, positive control), or saline solution (negative control). After insertion of a pressure-equalizing tube, pretreatment auditory brainstem responses (ABRs) were obtained. Topical solutions of 0.1 ml were applied through the tube into the middle ear twice a day for 7 days. Post-treatment ABRs were obtained 7 days after the last treatment. Hair cell loss was investigated with whole-mount cochlear surface preparations. Results: The saline-treated (negative control) group showed no deterioration of ABR threshold. The daptomycin-treated group showed mild deterioration and the gentamicin-treated group showed severe deterioration in ABR threshold. Hair cells were preserved in the daptomycin- and saline-treated groups but severely damaged in the gentamicin group.

Original languageEnglish
Pages (from-to)679-683
Number of pages5
JournalActa Oto-Laryngologica
Issue number7
Publication statusPublished - 2014 Jul


  • Drug-resistant
  • Eardrop
  • Hearing
  • Methicillin-resistant Staphylococcus aureus
  • Topical
  • Vancomycin

ASJC Scopus subject areas

  • Otorhinolaryngology


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