## **Core Concept**
Aminoglycosides are a class of antibiotics known for their potential to cause ototoxicity, which can manifest as cochleotoxicity (damage to the cochlea, leading to hearing loss) or vestibulotoxicity (damage to the vestibular system, leading to balance issues). The degree of cochleotoxicity varies among different aminoglycosides.

## **Why the Correct Answer is Right**
Neomycin is recognized for its high degree of cochleotoxicity. It is often used topically in otolaryngology for its antimicrobial properties but is not used systemically due to its high potential for ototoxicity. Neomycin primarily affects the cochlea, leading to hearing loss. This is because it can accumulate in the inner ear and cause damage to the hair cells.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Gentamicin is more vestibulotoxic than cochleotoxic. It can cause both vestibular and cochlear damage but is particularly noted for its vestibulotoxic effects.
- **Option B:** Tobramycin has a lower incidence of ototoxicity compared to some other aminoglycosides like neomycin. It can cause both cochlear and vestibular toxicity but is not the most cochleotoxic.
- **Option D:** Streptomycin is primarily vestibulotoxic. It was one of the first aminoglycosides discovered and is still used for the treatment of certain infections, notably tuberculosis and plague, but its use is limited due to its potential for ototoxicity, mainly vestibulotoxicity.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the risk of ototoxicity with aminoglycosides can be increased by factors such as higher doses, longer duration of treatment, pre-existing renal impairment, and concomitant use of other ototoxic drugs. Neomycin's high cochleotoxicity makes it particularly risky for patients where preservation of hearing is crucial.

## **Correct Answer:** . Neomycin