The fluoroquinolone antibacterials: past, present and future perspectives

Area of Science:

• Medicinal Chemistry
• Pharmacology
• Microbiology

Background:

• Quinolones, starting with nalidixic acid, have evolved significantly through structural modifications.
• Early fluoroquinolones like norfloxacin and ciprofloxacin offered broad-spectrum activity, particularly against Gram-negative bacteria.
• Despite clinical success, limitations in activity against Gram-positive bacteria and emerging resistance necessitated further research.

Purpose of the Study:

• To trace the historical development and structural evolution of quinolone antibiotics.
• To evaluate the advancements in fluoroquinolone research focusing on overcoming existing limitations.
• To assess the efficacy and spectrum of newer generation fluoroquinolones against resistant pathogens.

Main Methods:

• Literature review of quinolone development and structure-activity relationships.
• Analysis of clinical data and market trends for quinolone antibiotics.
• Comparative assessment of the antimicrobial spectrum and pharmacokinetic properties of various fluoroquinolones.

Main Results:

• Structural modifications have led to improved fluoroquinolones with enhanced activity and bioavailability, enabling once-daily dosing.
• Newer agents like gatifloxacin, moxifloxacin, and trovafloxacin show improved activity against Gram-positive cocci and anaerobes.
• While some newer fluoroquinolones retain activity against resistant strains, their clinical adequacy and potential side effects like phototoxicity require further investigation.

Conclusions:

• Fluoroquinolone development has progressed significantly, addressing many earlier limitations.
• Ongoing research aims to further enhance activity against resistant strains and improve safety profiles.
• Balancing efficacy, spectrum, and safety remains a critical aspect of fluoroquinolone antibiotic development.