An intensive care unit reports increasing gentamicin and tobramycin resistance among Gram-negative isolates, driven by plasmid-encoded aminoglycoside-modifying enzymes. Which aminoglycoside retains the most reliable activity against such multiresistant strains?

• A Streptomycin
• B Netilmicin
• C Neomycin
• D Amikacin ✓

Explanation

Amikacin is a semisynthetic derivative of kanamycin bearing an L-hydroxyaminobutyryl side chain that sterically hinders most aminoglycoside-modifying enzymes, so it resists inactivation by the majority of them. It is therefore the agent of choice when enzymatic resistance to gentamicin and tobramycin is prevalent. Neomycin is limited to topical and oral use.

Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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