Clinicai dose-finding study on azithromycin in the treatment of skin and skin structure infections

Abstract

A multicenter clinical trial was conducted to determire an appropriate dosing of azithromycin (AZM), a new 15-membered antibiotic macrolide, in the treatment of skin and skin structure infections. AZM at 250 mg a day for three days (L-group), AZM at 500 mg a day for three days (H-group) and cefaclor at 250 mg t. i. d. for 7-10 days were compared. Patients were assigned randomly to a drug group after informed consent had been obtained. The L-group and H-group were given AZM in a double-blind fashoon. The C-group was not blinded. The infections treated were (1)deep-seated hair follicle infections: furuncle, furunculosis and carbuncle;(2)diffuse deepseated infestions: cellulitis, erysipelas, lymphangitis, and lymphadenitis:(3)miscellaneous abscesses: subcutaneous abscess, suppurative hidradenitis, and infected atheroma. The total number of patients enrolled was 76 (L-group, 24; H-group, 25; C-group, 27). Clinical efficacy was evaluated in 68 patients (L-group, 22; H-group, 22; C-group, 24). Safety was analyzed in 74 patients (Lgroup, 22; H-group, 22; C-group, 24). Clinical usefulness was evaluated in 68 patients (L-group, 22; H-group, 22; C-group, 24). Clinical efficacy rates were 77.3% for the L-group, 90.9% for the H-group, and 66.7% for C-group. Differences were not statistically significant. The overall clinical improvement rates on days 3 and 5 were in descending order of H-group<L-group≥Cgroup. Differences were not statistically significant. Safety rates were 83.3% for the L-group, 87.5% for the H-group, and 88.5% for the C-group. Differences were not statistically significant. Usefulness rates were 77.3% for the L-group, 90.9% for the H-group, and 66.7% for the Cgroup. Differences were not statistically significant. Bacteriologic response rates were 80.0% for the L-group, 93.8% for the H-group, and 69.2% for the C-group. The incidence of adverse reactions and abnormal laboratory findings were low in all three groups, and were all mild. These results suggest that the appropriate dosage of azithromycin is 500 mg once a day for 3 days in the treatment. of skin and skin structure infections.