Besivance, Vigamox, Zymaxid are examples of which generation of fluoroquinolones?

• A. First generation
• B. Second generation
• C. Fourth generation
• D. Third generation

Answer: (C)

These medicines are fourth-generation fluoroquinolones. This generation is defined by broader activity, especially strong coverage against gram-positive cocci such as Staphylococcus aureus and Streptococcus pneumoniae, along with good gram-negative activity and excellent penetration into ocular tissues. Besifloxacin, moxifloxacin, and gatifloxacin are all formulated for topical eye use and provide robust tear-film and corneal concentrations, making them effective for common anterior segment infections like conjunctivitis. Earlier generations were more limited in gram-positive coverage and tissue penetration, whereas fourth-generation agents extend effectiveness against a wider range of pathogens and better pharmacokinetics for ocular use.