The in vitro activity of and pathogen responses to
sparfloxacin were compared with those of standard
therapies for the treatment of patients with community-acquired
pneumonia, complicated skin or skin-structure
infections, urinary tract infections, acute bacterial exacerbations of
chronic bronchitis, and acute
maxillary sinusitis in 7 multicenter controlled trials in North America.
Sparfloxacin was administered orally as a 400-mg loading dose followed by 200 mg once daily for up to 10 days. The bacteriologic efficacy of
sparfloxacin (84% to 95%) was comparable to that of comparator drugs (77% to 100%).
Sparfloxacin was generally 2 to 8 times more active (minimum inhibitory concentration for 90% of strains tested [MIC90]: 0.03 to 0.5 microg/mL) than comparators against common pathogens isolated in
community-acquired infections, especially Streptococcus pneumoniae, including
penicillin-resistant strains; Moraxella catarrhalis; Haemophilus influenzae; Streptococcus pyogenes; and Staphylococcus aureus.
Sparfloxacin was also effective against Chlamydia and Mycoplasma species. The emergence of resistance was uncommon during
sparfloxacin therapy (0.3% of 1100 cases). Higher area under the plasma concentration-time curve/MIC and maximum plasma concentration/MIC ratios for
sparfloxacin were associated with clinical and bacteriologic efficacy, whereas lower ratios were associated with clinical and bacteriologic failure. The clinical efficacy of
sparfloxacin (80% to 95%) was comparable to that obtained with the comparator drugs (71% to 92%). In addition,
sparfloxacin was well tolerated and had an overall frequency of related adverse events similar to that of the comparators. There was a higher frequency of photosensitivity reactions but a lower level of digestive adverse events with
sparfloxacin compared with comparators.
Sparfloxacin is a suitable therapeutic alternative for the empiric treatment of
respiratory tract infections owing to its favorable pharmacokinetic profile and activity against typical and atypical respiratory tract pathogens, even in geographic areas with a high incidence of penicillin resistance.