Question

Which of the following is not an aminoglycoside?

• A. Gentamycin
• B. Streptomycin
• C. Kanamycin
• D. Azithromycin

Hint:

Suffix separation tip: - "-thromycin" suffix typically indicates a Macrolide (e.g., Azithromycin, Erythromycin). - "-mycin" or "-micin" suffixes without "thro" generally indicate Aminoglycosides (e.g., Streptomycin, Gentamicin).

Answer 1

The Correct Option is D

Understanding the Concept: Antibiotics are classified into specific chemical structural categories that determine their mechanisms of action and side effect profiles:
• Aminoglycosides: Composed of amino-modified sugars linked via glycosidic bonds. They are bactericidal agents that bind irreversibly to the 30S ribosomal subunit, causing misreading of mRNA. Examples include Streptomycin, Gentamicin, Kanamycin, Neomycin, and Amikacin.
• Macrolides: Consist of a large macrocyclic lactone ring attached to deoxy sugars. They are bacteriostatic agents that bind to the 50S ribosomal subunit to inhibit bacterial protein translation. Examples include Erythromycin, Clarithromycin, and Azithromycin.

Step 1: Identify the non-aminoglycoside drug.
Azithromycin belongs to the macrolide class of antibiotics, not the aminoglycoside class. This makes it the correct choice for this question.