Dirithromycin in the treatment of skin and skin structure infections

The efficacy and safety of dirithromycin were compared with those of erythromycin or miocamycin for the treatment of skin and/or skin structure infections in two double-blind, double-dummy, randomized, parallel group, multicentre studies conducted in North America and in Europe, and one single-blind, randomized, parallel group study conducted in Italy. The US and European study patients, in which bacterial infection was confirmed by culture, received either dirithromycin 500 mg once daily or erythromycin base 250 mg four times daily for seven days. Patients in the Italian trial were treated with either 500 mg dirithromycin once daily or with 600 mg miocamycin twice daily for seven days. A total of 156 of the 304 US patients treated with dirithromycin and 127 of the 274 patients treated with erythromycin qualified for efficacy analysis post-therapy. At the post-therapy evaluation, 112 (71.8%) dirithromycin-treated patients were cured and 34 (21.8%) improved compared with 94 (74.0%) and 25 (19.7%) patients treated with erythromycin. The pathogen was eliminated or presumably eliminated in 136 (87.2%) and 110 (86.6%) dirithromycin- and erythromycin-treated patients, respectively. A total of 100 of the 193 dirithromycin-treated patients qualified for efficacy analysis, as did 99 of the 198 erythromycin-treated patients in the European study at post-therapy. Favourable clinical responses (cure or improvement) at the post-therapy visit were recorded in 96 (96.0%) dirithromycin- and 98 (99%) erythromycin-treated patients, and pathogens were eliminated or presumed to have been eliminated in 87 (87.0%) and 88 (88.9%) patients respectively, in the dirithromycin and erythromycin treatment groups. Efficacy analysis was performed in 56 of the 70 Italian patients treated with dirithromycin and in 62 of the 71 patients treated with miocamycin. At post-therapy evaluation, a favourable clinical response was observed in 98.2% of the dirithromycin-treated patients compared with 95.1% of miocamycin-treated patients, whereas a favourable bacteriological response was observed in 52 (92.9%) dirithromycin- and 52 (83.9%) miocamycin-treated patients respectively. In all studies no serious treatment-related events were noted. Events most frequently reported were gastrointestinal in nature. Overall in the three studies, no statistically significant differences were observed between two treatment groups in the clinical and bacteriological outcomes.