Comparative efficacy of 5 days of dirithromycin and 7 days of erythromycin in skin and soft tissue infections.

We investigated the comparative efficacy and safety of dirithromycin and erythromycin in the treatment of skin and soft tissue infections in this double-blind, randomized, multicentre study, in which 439 patients were randomized to treatment with dirithromycin (500 mg daily for 5 days) or erythromycin (250 mg every 6 h for 7 days). All randomized patients were included in the termination analysis, which showed that 187 of 220 (85.0%) dirithromycin recipients and 177 of 219 (80.8%) erythromycin recipients were clinically cured or improved (95% confidence interval (CI) -3.0% to +11.4%). In the termination analysis of the 211 bacteriologically evaluable patients, clinical cure or improvement occurred in 83 of 100 (83%) dirithromycin recipients and in 89 of 111 (80.2%) erythromycin recipients (95% CI -7.8% to +13.4%), and bacteriological eradication occurred in 85 of 100 (85%) and 89 of 111 (80.2%), respectively. Adverse events were similar in incidence and nature between the two groups, except that there was less nausea with dirithromycin (3.6% versus 8.2%; P = 0.042). Ten of 220 (4.5%) dirithromycin recipients and 27 of 219 (12.3%) erythromycin recipients returned >20% of their prescribed medication (P = 0.033). In the treatment of skin and soft tissue infections, dirithromycin (500 mg daily for 5 days) was comparable in efficacy to, and caused significantly less nausea than, erythromycin (250 mg every 6 h for 7 days). Compliance with the dirithromycin regimen was superior to that with the erythromycin regimen.