Topical quinolone nadifloxacin (OPC-7251) in bacterial skin disease: Clinical evaluation in a multicenter open trial and in vitro antimicrobiological susceptibility testing

Nadifloxacin (OPC-7251) is a topical fluoroquinolone which inhibits the configuration of supercoiled DNA by DNA gyrase. Previous studies have shown the efficacy of this topical agent in acne vulgaris. The purpose of this open study (clinical phase II) was to investigate the clinical efficacy and tolerability of nadifloxacin 1% cream applied topically in 101 patients with impetigo, secondarily infected wounds, folliculitis and sycosis vulgaris, and impetiginized dermatitis. Efficacy was assessed by counts of lesions and crusts, evaluation of objective and subjective symptoms, and microbiological isolation and identification of aerobic and anaerobic bacteria at baseline and at the end (day 7, or 14, respectively) of the study. The antibacterial activity of nadifloxacin against isolated bacterial strains was also tested in vitro by an agar dilution technique. Nadifloxacin treatment led to a statistically significant reduction in the degree of erythema, exudation, swelling, pain, pruritus, erosion, crusts and scaling, and eradication of causative bacteria was achieved. Three patients reported adverse effects (itching, erythema and inflammatory swelling each in one patient). Physicians' judgement on efficacy and tolerability was 'very good' or 'good' in 92% of the patients. Nadifloxacin was active against all aerobic and anaerobic isolates. Causative Staphylococcus aureus, beta-hemolytic streptococci and coagulase-negative staphylococci were eradicated in 83%, 100% and 68% of patients, respectively. Minimum inhibitory concentrations were 0.05 - 0.02 mu g/ml for S. aureus, 0.05 - 3.13 mu g/ml for coagulase-negative staphylococci, 0.05 - 0.78 mu g/ml for beta-hemolytic streptococci and 0.05 - 0.78 mu g/ml for Propionibacterium ames. All organisms isolated from the lesions before and at the end of the study were highly sensitive and none was resistant to nadifloxacin. In summary, nadifloxacin, a topical quinolone, is a new alternative for topical antibiotic treatment in bacterial skin infection.