Evaluation of the effect of gemcitabine on cochlea by otoacoustic emission in experimental animal model.

OBJECTIVES In this study, we aimed to search whether gemcitabine - a commonly used antimetabolite type antineoplastic agent-has ototoxic effect. STUDY DESIGN AND SETTING An experimental animal research. SUBJECTS AND METHODS We evaluated the effect of gemcitabine on hearing through its possible effect on cochlea by using otoacoustic emission method on experimental rat model. For this purpose 16 healthy adult male Wistar albino rats were used and these were divided into 4 groups. The rats in the 1st, 2nd, 3rd and the 4th groups were given 40-160-240 and 320 mg/kg of intraperitoneal gemcitabine respectively. Distortion product otoacoustic emission measurements on both ears of each rat were performed before and 1 week after administration of gemcitabine. The mean of signal to noise ratio of emission values obtained from each rat before and after the drug administration were calculated. RESULTS Rats in the 1st group had no statistically significant difference at the emission rates before and after gemcitabine administration. A statistically significant decrease was observed in the emission rates at emission values of only 5 kHz in the 2nd group, at 4-6 kHz in the 3rd group, at 4-5-6-8 kHz in the 4th group. CONCLUSIONS Gemcitabine causes a decrease in otoacoustic emission values on experimental rat models at high doses and especially at high frequencies. Larger clinical and laboratory studies are needed to determine whether this decrease in emission rates are permanent and whether it has any permanent effect on hearing.