Experimental investigation of intratimpanically applied 5-fluorouracil ototoxicity

Aim: The aim of this study was to investigate whether the solution form of 5-fluorouracil which is known to be effective cream form in the treatment of cholesteatoma causes ototoxicity by intratympanic administration. Material and Method: 11 male Wistar rats, right and left ear, mean 4 months, weighing 300-400 g were included in the study. In the control group (Group 1), 4 rat, amikacin with known toxicity was applied to positive controls and in the study group (Group 2), 7 rat, 5-fluorouracil was administered intratympanic. Drug treatment was applied to the right ear of both groups and no procedure was performed to the left ear. The study group was divided into 3 with 5-fluorouracil, one dose, two doses and three doses with one week intervals. The rats in the control group were sacrificed one week after the amikacin application and the rats in the study group were sacrificed one week after the target dose and was examined light microscopy and TUNEL method histopathologically. Results: Amikacin group and 5-fluorouracil was applied between the two groups showed differences in light microscopic parameters, but the difference was found significant in terms of apoptosis(p<0,05). The difference between the striae vascularis thickness was significant between the two groups(p<0,05). 5-fluorouracil group in the internal grouping, although the small number of subjects was not significant difference in terms of apoptosis(p<0,05). Conclusion: Although 5-fluorouracil administered intratympanicly in rats caused cellular changes, no autotoxic effect was detected in histopathological examination by evaluating apoptosis.