|Systematic (IUPAC) name|
|Pregnancy cat.||B U.S.|
|Legal status||Not FDA approved for clinical use in the United States|
|Half-life||6-7 hours, significantly longer in renal impairment|
|Mol. mass||232.235 g/mol|
|(what is this?)|
In the technical sense, it is a naphthyridone, not a quinolone: its ring structure is a 1,8-naphthyridine nucleus that contains two nitrogen atoms, unlike quinoline, which has a single nitrogen atom.
Nalidixic acid is effective against both gram-positive and gram-negative bacteria. In lower concentrations, it acts in a bacteriostatic manner; that is, it inhibits growth and reproduction. In higher concentrations, it is bactericidal, meaning that it kills bacteria instead of merely inhibiting their growth.
It has historically been used for treating urinary tract infections, caused, for example, by Escherichia coli, Proteus, Shigella, Enterobacter, and Klebsiella. It is no longer clinically used for this indication in the USA as less toxic and more effective agents are available.
It is also a tool in studies as a regulation of bacterial division. It selectively and reversibly blocks DNA replication in susceptible bacteria. Nalidixic acid and related antibiotics inhibit a subunit of DNA gyrase and topoisomerase IV and induce formation of cleavage complexes. It also inhibits the nicking-closing activity on the subunit of DNA gyrase that releases the positive binding stress on the supercoiled DNA.
Hives, rash, intense itching, or fainting soon after a dose may be a sign of anaphylaxis. Common adverse effects include rash, itchy skin, blurred or double vision, halos around lights, changes in color vision, nausea, vomiting, and diarrhea. Nalidixic acid may also cause convulsions and hyperglycaemia.
Spectrum of bacterial susceptibility and resistance
Aeromonas hydrophila, Clostridium and Haemophilus are generally susceptible to nalidixic acid, while other bacteria such as Bifidobacteria, Lactobacillus, Pseudomonas and Staphylococcus are resistant.
- Emmerson, A. M.; Jones, A. M. (2003). "The Quinolones: Decades of Development and Use" (pdf). The Journal of Antimicrobial Chemotherapy 51 (Suppl 1): 13–20. doi:10.1093/jac/dkg208. PMID 12702699.
- Pommier, Y., Leo, E., Zhang, H., Marchand, C. 2010. DNA topoisomerases and their poisoning by anticancer and antibacterial drugs. Chem. Biol. 17: 421-433.
- Fraser, A. G.; Harrower, A. D. (December 1977). "Convulsions and Hyperglycaemia Associated with Nalidixic Acid". British Medical Journal 2 (6101): 1518. doi:10.1136/bmj.2.6101.1518. PMC 1632822. PMID 589309.
- "Nalidixic acid spectrum of bacterial susceptibility and Resistance" (pdf). Toku-E. 2011-09-14. Retrieved 2012-05-14.