Which drug is a member of the tetracycline class?

• A. Minocycline
• B. Amoxicillin
• C. Rifampicin
• D. Ofloxacin

Answer: (A)

Minocycline is a tetracycline antibiotic. Tetracyclines work by reversibly binding to the 30S subunit of bacterial ribosomes, blocking the attachment of aminoacyl-tRNA and thereby inhibiting protein synthesis. This mechanism is characteristic of the tetracycline class, which also includes drugs like doxycycline and tetracycline.

The other drugs shown belong to different antibiotic classes: amoxicillin is a beta-lactam that inhibits cell wall synthesis; rifampicin inhibits DNA-dependent RNA polymerase; and ofloxacin is a fluoroquinolone that targets DNA gyrase/topoisomerase IV. Hence, minocycline is the correct member of the tetracycline class.