Sparfloxacin is a piperazinyl, cyclopropyl-fluoroquinolone with broad-spectrum antibacterial activity. Compared to other quinolones, sparfloxacin displays improved activity against a variety of pathogens including Staphylococcus, Streptococcus, Enterococcus, Chlamydia, Mycoplasma, Ureaplasma, and Mycobacteria species. Other susceptible organism group include Haemophilus, Legionella, Moraxella, Neisseria, Aeromonas, Acinetobacter, Bordetella, Brucella, Campylobacter, Gardnerella, and Helicobacter species. Most Enterobacteriaceae are also susceptible, whereas most isolates of Pseudomonas aeruginosa are not. Sparfloxacin is bactericidal. Activity is generally stable to variations of inoculum, pH, and cation concentration, and it is unchanged in the presence of 5% sodium cholate or 70% human serum. Susceptibility to the drug is diminished in urine. Cross-resistance, although incomplete, has been documented with other quinolones, but not with other antimicrobic classes.