Which antibiotic class is commonly used for bacterial conjunctivitis and includes drugs such as ciprofloxacin and levofloxacin?

• A. Fluoroquinolones
• B. Macrolides
• C. Aminoglycosides
• D. Tetracyclines

Answer: (A)

Fluoroquinolones are a widely used class for bacterial conjunctivitis because they are broad‑spectrum, targeting both common gram‑positive and gram‑negative ocular pathogens with rapid bactericidal action. Ciprofloxacin and levofloxacin are members of this class, and they work by inhibiting bacterial DNA gyrase and topoisomerase IV—enzymes essential for DNA replication. This mechanism allows these drugs to kill bacteria quickly when applied topically to the eye, and they penetrate ocular tissues well, making them effective as eye drops. Their spectrum covers usual culprits in conjunctivitis, and they’re especially valuable for cases where Pseudomonas is a concern, such as in contact lens wearers. Other antibiotic classes exist with different spectrums and uses, but the drugs named in the question are classic examples of fluoroquinolones.