Identifying aminoglycoside antibiotics by class membership Which one of the following is <em>not</em> classified as an aminoglycoside?

Introduction / Context:
Aminoglycosides are bactericidal protein synthesis inhibitors effective against aerobic gram-negative bacilli and some gram-positive organisms in synergy. Knowing which agents belong to this class helps anticipate nephrotoxicity, ototoxicity, and spectrum.

Given Data / Assumptions:

• Aminoglycosides bind to the 30S ribosomal subunit and cause misreading.
• Common examples include streptomycin, gentamicin, neomycin, and kanamycin.
• Cephalosporins are beta-lactams and mechanistically distinct.

Concept / Approach:
Classify each option by its known scaffold and target. Streptomycin, neomycin, kanamycin, and gentamicin are authentic aminoglycosides. Cephalosporins inhibit cell wall synthesis via PBPs and the beta-lactam ring, not the ribosome.

Step-by-Step Solution:
List aminoglycosides: streptomycin, gentamicin, neomycin, kanamycin, amikacin, tobramycin.Identify the outlier: cephalosporin is a beta-lactam.Select “Cephalosporin.”

Verification / Alternative check:
Pharmacology texts and drug monographs confirm class assignments.

Why Other Options Are Wrong:
They are true aminoglycosides and share toxicity and spectrum features typical of the class.

Common Pitfalls:
Confusing bactericidal beta-lactams with bactericidal aminoglycosides because both may be used for severe infections.

Final Answer:
Cephalosporin.