Antioxidants in the Prevention of Cisplatin-Induced Hearing Loss: A Systematic Review and Meta-Analysis

Abstract

Abstract Background Cisplatin is a commonly used chemotherapeutic drug that is associated with irreversible hearing loss. A number of antioxidants have been investigated for prevention, but data have so far been inconclusive. Objective The objective of this study was to assess the efficacy of various antioxidant therapies in preventing hearing loss among adult patients treated with cisplatin. Methodology We searched for controlled clinical trials evaluating various antioxidants as prevention against cisplatin-induced hearing loss in adults. The primary outcome is the proportion of patients with hearing loss. Secondary outcomes include audiometric threshold shifts, tinnitus, tumor response, adverse events, and quality of life. Results Thirteen randomized trials comprising of nine antioxidant therapies were included. Only coenzyme Q with multivitamins demonstrated significant benefit in preventing cisplatin-induced hearing loss (relative risk: 0.15, 95% confidence interval: 0.04–0.58) in a small study, while data for the rest of the agents were inconclusive. Audiometric threshold shifts were significantly lower in the intervention arm for aspirin, vitamin E, and transtympanic dexamethasone. The available data on tumor response was inconclusive, with no definite evidence of diminished tumor response noted. Adverse events noted include mild ear pain particularly for transtympanic therapies. There was no data available on quality of life. Conclusion The current available evidence is so far insufficient to establish any benefit for antioxidant therapies for the prevention of cisplatin-induced hearing loss. More high-quality studies are needed to fill in the identified gaps in knowledge.