The protective role of N-acetyl systein and salicilat in cisplatin ototoxcity

Cisplatin is a widely used and effective chemotherapeutic agent but has a highincidence of toxicities, including ototoxicity. Ototoxicity is a common and major drawback toCP therapy that both reduces quality of life and restricts treatment protocols. It is currently theprimary dose limiting factor in CP therapy. Methods to decrease this effect would increase theuse and dosages of the effective platinum based chemotherapeutic agents, thereby improvingefficacy. Since, CP is a indispensable agent, reducing its toxic effect will allow to use thehigher and more effective doses clinically. In this respect, using protective agents may reduceits toxic effects and this issue became a wide subject of investigation. NAC and salisilat areknown has protective and antioxidan effects. In our study, we investigated if these agentshave protective effects against cisplatin ototoksicity using audiometry and ABR.In our study, using NAC was found to be protective in 10.000 and 12.000 Hz. AgainstCP ototoxicity. Protective effect of NAC is consistent with many other studies, however, thereis some concern about if NAC may reduce antitumor activity of CP.Salisilat is a drug widely used all over the world. It has antioxidant property, and mayact a possible otoprotektor against the action of CP. Studies about salisilat otoprotectionmostly consist of experimental studies, however, clinical studies are rare. In our study,contrarily the NAC, we could not find any protective effect in patients received salisilat usingaudiometry and ABR. Structural differences between the human and the animal cochlea,difficulties in cooperation of audiometric tests, and difficulties in providing homogen groupsin clinical studies may responsible about the result of our study and further studies willneeded.Based on our study, no any significant differences was found in ABR finding eitherwith using NAC or salisilat. This result differs with some data in the literature. Our negativeABR results may be due to: 1) Knowing that CP has an ototoxic action by damaging the outerhair cells in cochlea, and audiometry is a more sensitive method to show cochlear lesions, 2)Clinical studies has difficulty in providing homogenous groups regardind the patients? age,sex, ear pathologies, and systemic diseases, 3) Risk factors for ototoxicity due to cisplatin,depends on the patients? decreased blood serum albumin, hemoglobin, red blood cell countand hematocryt levels