THE COMPARATIVE EFFECTS OF SODIUM THIOSULFATE, DIETHYLDITHIOCARBAMATE, FOSFOMYCIN AND WR-2721 ON AMELIORATING CISPLATIN-INDUCED OTOTOXICITY

The efficacies of four agents in ameliorating cisplatin-induced ototoxicity were investigated. Hamsters were given a series of 5 cisplatin injections (3 mg/kg/injection once every other day, i.p.) either alone or in combination with 1600 mg/kg/injection sodium thiosulfate (STS), 300 mg/kg/injection diethyldithiocarbamate (DDTC), 18 mg/kg/injection WR-2721, or 300 mg/kg/injection fosfomycin (n = 10/group). Ototoxicity was assessed electrophysiologically by auditory brainstem responses (ABRs) and anatomically by cochlear histology. The greatest auditory protection was given by STS, followed by DDTC. WR-2721 and fosfomycin did not provide any protection. All of the animals in the STS and DDTC groups survived, while some fatalities occurred in the fosfomycin, WR-2721, and cisplatin-only groups. Thus, the agents that were protective against ototoxicity were also protective against mortality. The ABRs also provided evidence of cisplatin-induced neuropathy. In summary, STS and DDTC hold promise for ameliorating the ototoxic effects of cisplatin chemotherapy and the hamster proved to be an excellent model of cisplatin ototoxicity.