Comparison of the in vitro activity of and pathogen responses to sparfloxacin with those of other agents in the treatment of respiratory tract, urinary tract, and skin and skin-structure infections

The in vitro activity of and pathogen responses to sparfloxacin were compar ed with those of standard therapies for the treatment of patients with comm unity-acquired pneumonia, complicated skin or skin-structure infections, ur inary 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 fol lowed 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 inhi bitory concentration for 90% of strains tested [MIC90]: 0.03 to 0.5 mu g/mL ) than comparators against common pathogens isolated in community-acquired infections, especially Streptococcus pneumoniae, including penicillin-resis tant strains; Moraxella catarrhalis; Haemophilus influenzae; Streptococcus pyogenes; and Staphylococcus aureus. Sparfloxacin was also effective agains t Chlamydia and Mycoplasma species. The emergence of resistance was uncommo n during sparfloxacin therapy (0.3% of 1100 cases). Higher area under the p lasma concentration-time curve/MIC and maximum plasma concentration/MIC rat ios for sparfloxacin were associated with clinical and bacteriologic effica cy, whereas lower ratios were associated with clinical and bacteriologic fa ilure. The clinical efficacy of sparfloxacin (80% to 95%) was comparable to that obtained with the comparator drugs (71% to 92%). In addition, sparflo xacin was well tolerated and had an overall frequency of related adverse ev ents similar to that of the comparators. There was a higher frequency of ph otosensitivity reactions but a lower level of digestive adverse events with sparfloxacin compared with comparators. Sparfloxacin is a suit able therap eutic alternative for the empiric treatment of respiratory tract infections owing to its favorable pharmacokinetic profile and activity against typica l and atypical respiratory tract pathogens, even in geographic areas with a high incidence of penicillin resistance.