Mechanism
Inhibits DNA gyrase in Gram-negative bacteria and topoisomerase in Gram-positive bacteria, thereby inhibiting bacterial DNA synthesis.
History
| History | Effect | |
|---|---|---|
| To replace the antimalarial drug quinine (extracted from cinchona), chloroquine was invented (higher efficacy and lower adverse reactions) While Sterling Winthrop was researching better synthesis methods for chloroquine, nalidixic acid (the world’s first quinolone drug) was accidentally discovered. Based on nalidixic acid, the first generation quinolone drugs were developed (nalidixic acid, pipemidic acid, oxolinic acid, flumequine, etc.) |
Narrow antibacterial spectrum, effective only against some Gram-negative bacteria |
|
| Kyorin Pharmaceutical in Japan invented the second generation (collectively called fluoroquinolones) — [[Norfloxacin]] (quinolone plus a fluorine atom). Bayer added a carbon atom to norfloxacin to invent the more effective [[Ciprofloxacin]] | Effective against most Gram-negative bacteria, some Gram-positive bacteria, and Pseudomonas aeruginosa | More stable pharmacokinetics, fewer side effects |
| Daiichi Sankyo in Japan invented the third generation — [[Levofloxacin]] | Stronger effect than the second generation | |
| Fourth generation — [[Gatifloxacin]], [[Moxifloxacin]], [[Gemifloxacin]] | Effective against G+, G-, Pseudomonas aeruginosa, anaerobes, chlamydia, mycoplasma, and some intracellular pathogens | Rapid absorption, wide distribution in the body, long half-life |
[[Quinolones]]
Adverse Reactions
- Contraindicated in minors and pregnant women. May cause damage to articular cartilage, especially weight-bearing joints.
- Use with caution in athletes and the elderly; can cause tendinitis and tendon rupture.
- Prolongation of the QT interval on ECG.
- Blood sugar disorders.