The effect of intratympanic vitamin C administration on cisplatin-induced ototoxicity.

The objective of this study is to investigate the effect of intratympanic injection of vitamin C on cisplatin-induced ototoxicity. The study included 24 albino adult female rats (48 ears). The study animals were divided into four groups each of which was composed of six animals including a control (intraperitoneal cisplatin), a cisplatin-saline (saline intratympanic + intraperitoneal cisplatin), a C vit (intratympanic vitamin C) and a cisplatin-C vit group (intraperitoneal cisplatin + intratympanic vitamin C). As two animals had died due to cisplatin-induced ototoxicity (one in the control and one in the cisplatin-saline group) they were excluded from the study. The experiment was terminated, performing distortion product otoacoustic emission (DPOAE) measurement prior to procedures and at the end of the experiment. The results of the statistical analysis were evaluated. In the cisplatin-C vit group, there were no significant decreases in DPOAE amplitudes at 2 kHz (p > 0.05). Although a decrease was observed in DPOAE amplitudes at 2.8, 4, 6, and 8 kHz frequencies, these amplitude reductions were significantly lower than the control group (p < 0.05). Intratympanic vit C infusion provided a protective effect against cisplatin-induced ototoxicity primarily at 2 kHz and at other frequencies (2.8, 4, 6, and 8 kHz), and it did not produce a toxic effect in the cochlea.