Which of the antibiotics is likely to impair hearing?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2016

Pharmacology

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2016

Explanation

Neomycin is an aminoglycoside antibiotic with the highest potential for causing cochleotoxicity, which is damage to the cochlea of the inner ear, leading to hearing loss.
Medical literature specifically identifies Neomycin as the most likely agent among aminoglycosides to cause auditory damage.
Due to its severe ototoxicity and nephrotoxicity, Neomycin's systemic (IV/IM) use is avoided, and it is primarily used topically or orally for local effects where absorption is minimal.
The question asks which antibiotic is likely to impair hearing, referring to its inherent pharmacological property, and Neomycin is the most potent in this regard.

Option A: Streptomycin is an aminoglycoside known for ototoxicity, but its primary effect is on the vestibular system, causing balance issues like vertigo and ataxia, rather than primarily affecting hearing.
Option C: Erythromycin is a macrolide antibiotic. While ototoxicity can occur, it is a rare side effect, typically associated with high doses or renal impairment, and is usually reversible. Aminoglycosides are far more likely to cause permanent hearing damage.
Option D: Gentamicin, like Streptomycin, is an aminoglycoside whose ototoxic effects are primarily vestibulotoxic, affecting balance more than hearing.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Ototoxicity as an adverse effect of antibiotics as background academic context rather than a clinical decision trigger.
When administering any aminoglycoside, nurses must perform baseline hearing and balance assessments and monitor for symptoms like tinnitus (ringing in ears), hearing loss, or vertigo.
Therapeutic drug monitoring (measuring peak and trough levels) is crucial for aminoglycosides to ensure efficacy while minimizing the risk of ototoxicity and nephrotoxicity. Trough levels above 2 mcg/mL are associated with increased risk.
Patient education should include instructions to immediately report any changes in hearing, ringing in the ears, or dizziness.

How to Approach the Question

First, identify the core concept of the question, which is a specific adverse effect (hearing impairment) of a drug class (antibiotics).
Categorize each option by its drug class. Streptomycin, Neomycin, and Gentamycin are aminoglycosides. Erythromycin is a macrolide.
Recall the major, well-known toxicities associated with these classes. Aminoglycosides are famous for ototoxicity and nephrotoxicity ('can't hear, can't pee').
Differentiate within the aminoglycoside class. While all are ototoxic, recall or look for the specific type of ototoxicity. The question asks about 'hearing' (auditory/cochlear), not 'balance' (vestibular).
Select the option most specifically associated with auditory damage. Literature confirms Neomycin is the most cochleotoxic.

Concept Tested & Keywords

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E6 Pharmacology Katzung 16e p. 1286-1288

E6 Pharmacology Nursing Lilley 11e Part 2 p. 317-319