The antibacterial action of gatifloxacin results from inhibition of DNA gyrase and topoisomerase IV. DNA gyrase is an essential enzyme that is involved in the replication, transcription and repair of bacterial DNA. Topoisomerase IV is an enzyme known to play a key role in the partitioning of the chromosomal DNA during bacterial cell division. The mechanism of action of fluoroquinolones including gatifloxacin is different from that of aminoglycoside, macrolide, and tetracycline antibiotics. Therefore, gatifloxacin may be active against pathogens that are resistant to these antibiotics and these antibiotics may be active against pathogens that are resistant to gatifloxacin. There is no crossresistance between gatifloxacin and the aforementioned classes of antibiotics. Cross resistance has been observed between systemic gatifloxacin and some other fluoroquinolones. Resistance to gatifloxacin in vitro develops via multiple-step mutations.
Zymar Eye Drop 0.3%
0.3% eye drops-
The recommended dosage regimen for the treatment of bacterial conjunctivitis is:
Days 1 and 2: Instill one drop every two hours in the affected eye(s) while awake, up to 8 times daily.
Days 3 through 7: Instill one drop up to 4 times daily while awake.
0.5% eye drops-
Patients 1 year of age or older: Instill one drop every two hours in the affected eye(s) while awake, up to 8 times on Day 1. Instill one drop two to four times daily in the affected eye(s) while awake on Days 2 through 7.