Protective effect of edaravone against tobramycin-induced ototoxicity.
CONCLUSIONS
It is suggested that simultaneous treatment with the radical scavenger edaravone has an effective protective effect against tobramycin ototoxicity in rat. Even if the edaravone treatment is postponed for 7 days, it can still prevent hearing loss, but a 14 day delay cannot protect from ototoxicity.


OBJECTIVE
With the aim of alleviating hearing loss caused by aminoglycoside ototoxicity, we performed a trial to assess the hearing protective efficacy of the radical scavenger edaravone.


METHODS
In part one of the study, 21 male Sprague-Dawley albino rats were used; 2 rats served as controls for the safety of edaravone. Eight rats each received 10 subcutaneous injections (s.c.) of tobramycin (160 mg/kg b.w.) once daily and saline injection intraperitoneally for 2 weeks. Eleven rats were given 10 s.c. tobramycin injections simultaneously with an intraperitoneal injection of edaravone (3 mg/kg b.w.). In part two, tobramycin was injected in 13 rats (as above). Five of these received two edaravone injections 7 days later and four rats similarly 14 days later. Auditory brainstem response (ABR) was used to assess hearing.


RESULTS
All rats treated only with tobramycin showed a deterioration of hearing. None of the rats given simultaneous treatment with tobramycin and edaravone demonstrated hearing loss. A 7 day delay in edaravone injection still prevented hearing loss, but a 14 day delay had only a temporary prophylactic effect.
Asplund
Monika Stenkvist
MS
Department of Otolaryngology, Head & Neck Surgery, University Hospital, Uppsala, Sweden. monika.stenkvist.asplund@akademiska.se
Lidian
Adnan
A
Linder
Birgitta
B
Takumida
Masaya
M
Anniko
Matti
M
D000818:Animals; D000900:Anti-Bacterial Agents / Q000633:toxicity*; D000983:Antipyrine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004334:Drug Administration Schedule; D000077553:Edaravone; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006313:Hearing Loss, Central / Q000139:chemically induced / Q000517:prevention & control; D006319:Hearing Loss, Sensorineural / Q000139:chemically induced* / Q000517:prevention & control*; D007274:Injections, Intraperitoneal; D007279:Injections, Subcutaneous; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D014031:Tobramycin / Q000633:toxicity*
D000900:Anti-Bacterial Agents; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D000077553:Edaravone; D000983:Antipyrine; D014031:Tobramycin