Review of the 4-quinolones

Improvements in antimicrobial activity and pharmacokinetics have moved the 4-quinolones into the forefront of antibiotic research. The 4-quinolones are analogues of nalidixic acid, and there are presently at least six agents in this group under investigation in the United States. It is difficult to generalize their clinical usefulness, since these agents exhibit different pharmacokinetic profiles, antimicrobial activity (with varied minimum inhibitory concentrations among similar organisms), and dosage regimens. The 4-quinolones are potential therapeutic alternatives for infections caused by a variety of organisms. They include: Neisseria gonorrhoeae; Pseudomonas aeruginosa; Haemophilus influenzae; Staphylococcus aureus; common enteric pathogens (salmonella, shigella, campylobacter, etc); and intracellular bacteria (legionella, chlamydia, mycobacteria, etc). Clinical efficacy has been demonstrated in urinary tract infections, respiratory tract infections, and sexually transmitted diseases. Future studies will undoubtedly demonstrate effectiveness in numerous additional infectious processes. The purpose of this article is to compare the 4-quinolones in regards to pharmacokinetics and spectrum of activity and review the clinical studies involving these agents.