Fluoroquinolones

The fluoroquinolones (fluoridated quinolones) are broad-spectrum bactericidal agents, that inhibit DNA gyrase, prevent DNA supercoiling and DNA synthesis.

They are active against P. aeruginosa, mycoplasma, chlamydia, staphylococci and a few of the streptococci.

Fluoroquinolones are useful in pneumonia, urinary tract infections, bacterial diarrhea, and skin and soft tissue infection.

These agents are metabolized in the liver and excreted in the urine.

The fluoroquinolone agent most used with pet rats is enrofloxacin. It’s human counterpart is ciprofloxacin.

With the exception of these two agents all other quinolones/fluoroquinolones are only available orally at the time of this writing.

Serious adverse reactions are reportedly few with the fluoroquinolones, however, seizures though rare have been reported, as well as sterile abscess’ with injections of enrofloxacin in rats.

It is known that the quinolone class of drugs have been shown to produce erosions of articular cartilage in weight bearing joints, as well as producing other signs of arthropathy in immature animals of various species, including juvenile rats (Kashida et al., 1997). However, evidence of cartilage abnormalities appear to be dose related (high dosages over extended period).

It is also important to note that although the use of fluoroquinolones have not been recommended for initial treatment in pregnant and nursing does or juvenile rats (under 4 months) due to the risks of cartilage abnormalities (Egerbacher et al., 2000), in cases where other antibiotics are not helping, or if the infection is deemed severe, the benefit of using fluoroquinolones (alone or in combination with other compatible antimicrobials) may, in fact, outweigh the risks.

Synergism can occur when aminoglycosides, cephalosporins and extended-spectrum penicillins are used with fluorinated quinolones. In cases where polymicrobial infections are suspected, use of such drugs that are synergistic may be very beneficial, especially when broader coverage is needed.

Finally, use caution when giving fluoroquinolones together with theophylline since those agents may raise theophylline levels.

For additional drug interactions or adverse reactions see individual agents.

Reference

Egerbacher, M., Seiberl, G., Wolfesberger, B., & Walter, I. (2000). Ciprofloxacin causes cytoskeletal changes and detachment of human and rat chondrocytes in vitro. Arch Toxicol, 73(10-11), 557-63. Retrieved December 20, 2008, from the PubMed database.