Sitafloxacin (Gracevit®) : an oral fluoroquinolone antibiotic inhibit bacterial DNA replication. Its targets are DNA gyrase and topoisomerase. In vitro study, sitafloxacin showed broad spectrum activity against gram negative, gram positive, anaerobic bacteria, and atypical pathogen.
Oral sitafloxacin is approved in Japan for bacterial infections such as pneumonia, urethritis, and pyelonephritis. No Clinical Laboratory and Standards Institute(CLSI) breakpoints for sitafloxacin susceptibility, so breakpoints for other fluoroquinolones are applied for interpretation.
According to MIC90 of sitafloxacin(MIC of sitafloxacin can inhibit 90% of bacterial isolates) its efficiency was greater than levofloxacin, ciprofloxacin, moxifloxacin, and tosufloxacin.
Although, major mechanism of fluoroquinolone is mutation of targets(DNA gyrase: gyrA and gyrB, topoisomerase: parC and parE), sitafloxacin demonstrated activity against bacteria with drug-target mutation.
Surprisingly, sitafloxacin had effective activity against many superbugs including methicillin-resistant S.aureus(MRSA), methicillin-resistant coagulase-negative staphylococci(MR-CNS), and carbapenem-resistant A.baumannii.
In vivo studies demonstrated effective activity of sitafloxacin against polymicrobial infections in rat uterine endometritis model, S.pneumoniae in mouse lung infection model, and H.influenzae pneumonia in murine model.
In respiratory tract infection study, 50 mg of sitafloxacin twice daily showed 100% eradication rate of pathogens including S.pneumoniae, H.influenzae, M.pneumoniae, and P.aeruginosa.
For complicated urinary tract infection, sitafloxacin 100 mg twice daily for 7 days eradicated up to 96% of pathogens including E.faecalis, E.coli, P.aeruginosa, and K.pneumoniae.
Moreover, oral sitafloxacin also showed effective activity in otorhinolaryngological infections, urethritis, C.trachomatis-associated cervicitis, odontogenic infections, otitis media, and paranasal sinusitis.
Keating GM. Sitafloxacin in bacterial infections. Drugs, April 2011.