Sparfloxacin versus ciprofloxacin for the treatment of community-acquired,complicated skin and skin-structure infections

Fluoroquinolones have been shown to be effective in the treatment of compli cated skin and skin-structure infections, in part because of their broad-sp ectrum antibacterial activity against causative pathogens that are resistan t to older antimicrobial agents. We enrolled 603 adult patients (>58% male, >85% white) in a double-masked, double-dummy, randomized, multicenter tria l to compare the efficacy and tolerability of sparfloxacin (400-mg loading dose followed by 200 mg once daily) with those of ciprofloxacin (750 mg twi ce daily) for 10 days in the treatment of community-acquired, complicated s kin and skin-structure infections. The primary efficacy variable was clinic al response, based on assessment of signs and symptoms, in the clinically a ssessable population. Patients in the sparfloxacin and ciprofloxacin groups were comparable with respect to demographic characteristics, underlying di seases, medical history, and laboratory test results. Wound infection was t he most common diagnosis, and Staphylococcus aureus was the most frequently isolated pathogen. For the 475 clinically assessable patients, the clinica l success rate (percentage of patients cured or improved) was 90.1% (210/23 3) with sparfloxacin and 87.2% (211/242) with ciprofloxacin. In this analys is (95% confidence interval [CI], -2.8 to 8.6) and the intent-to-treat anal yses (95% CI, -4.2 to 6.2), results with spar floxacin were statistically e quivalent to those with ciprofloxacin (95% CI, -1 to 15.3). For bacteriolog ically assessable patients, eradication rates were 87.0% (141/162) with spa rfloxacin and 79.9% (123/154) with ciprofloxacin (95% CI, -1 to 15.3). Erad ication rates of S aureus and coagulase-negative staphylococcal infections were 90.2% (101/112) with sparfloxacin and 77.9% (88/113) with ciprofloxaci n. For patients with 2 or more pathogens at baseline (mixed infections), ba cteriologic success was 87.6% for sparfloxacin and 77.9% for ciprofloxacin. Pseudomonas aeruginosa infections were eradicated or presumed eradicated i n 71.4% (10/14) of sparfloxacin-treated patients and 87.5% (7/8) of ciprofl oxacin-treated patients. Overall success rates in the bacteriologically ass essable patients for sparfloxacin (84.6% [137/162]) and ciprofloxacin (78.6 % [121/154]) were statistically equivalent (95% CI, -2.5 to 14.5). Tolerabi lity was assessed in all patients who received study medication. The overal l frequency of treatment-related adverse events was comparable in the 2 tre atment groups (26.5% sparfloxacin, 23.3% ciprofloxacin). Drug-related adver se events involving the digestive system occurred in 7.1% of sparfloxacin-t reated patients and 19.0% of ciprofloxacin-treated patients; photosensitivi ty reactions were reported in 11.1% of patients in the sparfloxacin group a nd 0.7% of patients in the ciprofloxacin group (P < 0.001). The mean change in QT,interval from baseline to the maximum on-treatment value was greater in the sparfloxacin group (9 milliseconds) than in the ciprofloxacin group (3 milliseconds) (P = 0.005; 95% CI, 0.002 to 0.010). The efficacy of spar floxacin was comparable to that of ciprofloxacin in the treatment of commun ity-acquired, complicated skin and skin-structure infections, including tho se caused by staphylococci, the most common pathogens. Sparfloxacin's once- daily regimen, high skin-tissue penetration, and improved activity against gram-positive cocci make it a therapeutic alternative to ciprofloxacin for patients who are not at risk for photosensitivity reactions or adverse even ts associated with prolongation of the QT(c) interval.