A 70-year-old patient on gentamicin therapy for gram-negative sepsis develops irreversible sensorineural hearing loss. The cochlear toxicity of aminoglycosides is primarily attributed to:

• A Blockade of potassium channels in the stria vascularis
• B Accumulation in and destruction of outer hair cells of the organ of Corti ✓
• C Vasospasm of cochlear microcirculation causing ischemia
• D Inhibition of mitochondrial protein synthesis in spiral ganglion neurons

Explanation

Aminoglycosides accumulate selectively in outer hair cells of the organ of Corti, where they generate reactive oxygen species (ROS) and cause irreversible cell death, leading to high-frequency sensorineural hearing loss. The basal turn of the cochlea (high-frequency region) is affected first and most severely. This ototoxicity is dose-dependent and potentiated by concurrent use of loop diuretics.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.