Main Categories Of Quinolones

Quinolones are divided into first, second and third generations according to their invention and their antibacterial properties.
The first-generation quinolones only have antibacterial effects against Escherichia coli, Shigella dysenteriae, Klebsiella, and a small number of Proteus. Specific varieties include Nalidixic acid and Piromidic acid, etc., which are now rarely used due to poor efficacy.
The second-generation quinolones have expanded their antibacterial spectrum and also have certain antibacterial effects against Enterobacter, Citrobacter, Pseudomonas aeruginosa, and Serratia. Piperic acid is the main application variety in China.
The antibacterial spectrum of third-generation quinolones has been further expanded, and it also has antibacterial effects on Gram-positive bacteria such as Staphylococcus aureus, and its antibacterial effect on some Gram-negative bacteria has been further enhanced.
The antibacterial spectrum of the fourth generation quinolones is the largest so far, and the antibacterial activity against most anaerobic bacteria and Gram-positive bacteria such as Pseudomonas aeruginosa is also significantly improved. For example, moxifloxacin, gatifloxacin, and clinfloxacin.