Ototoxicity: A Challenge in Diagnosis and Treatment

Abstract

Ototoxicity is the pharmacological adverse reaction affecting the inner ear or auditory nerve, characterized by cochlear or vestibular dysfunction. The panorama of drug-induced hearing loss has widened over last few decades. Although ototoxic medications play an imperative role in modern medicine, they have the capacity to cause harm and lead to significant morbidity. Evidence has shown early detection of toxicity through prospective ototoxicity monitoring allows for consideration of treatment modifications to minimize or prevent permanent hearing loss and balance impairment. Although many ototoxicity monitoring protocols exist, their practicality is questionable due to several factors. Even though the existing protocols have proven to be effective, certain lacunae in practice have been encountered due to discrepancies among recommended protocols. Implementation of these protocols is mostly held back due to the incapacitated status of the patient. The choice of early ototoxicity identification techniques is still debatable due to variables such as high degree of sensitivity, specificity and reliability, less time consumption and less labour-intensive to the patient. Hence, the diagnosis and effective treatment of ototoxicity is challenging, even today. A stringent protocol with more practicality encompassing all elements aimed at profiling the effects of ototoxicity is greatly needed. This review describes an efficient application of ototoxicity monitoring and treatment protocol as an attempt to reduce the challenges in diagnosis and management of ototoxicity.

Keywords: Distortion product of otoacoustic emission; High-frequency audiometry; Ototoxicity; Ototoxicity monitoring.

Fig. 1.

Ototoxicity monitoring protocol. PTA: pure tone audiometry, HFA: high frequency audiometry, SRO_BEH: sensitive range of ototoxicity using PTA and HFA, DPOAE: distortion product otoacoustic emission, SRO_DP: sensitive range of ototoxicity using DPOAE, THI: Tinnitus Handicapped Inventory, DHI: Dizziness Handicapped Inventory, ALD: assistive listening devices.

Fig. 2.

Standard high frequency audiogram, highlighting behavioural sensitivity range of ototoxicity thresholds. SRO_BEH: sensitive range of ototoxicity using PTA and HFA.