A total of 193 patients with streptococcal
pharyngitis/
tonsillitis received 500 mg
dirithromycin once daily and 196 patients 250 mg
erythromycin four times daily for ten days in a double-blind, parallel-group multicentre study. In the
dirithromycin treatment group, 97 (50.3%) patients completed the study and were evaluated for efficacy analysis, and 99/196 (50.5%)
erythromycin-treated were evaluated for efficacy of treatment. Favourable clinical responses to treatment (cure or improvement of symptoms) at the post-
therapy visit (three to five days after
therapy completion) occurred in 89 (91.7%)
dirithromycin- and 93 (93.9%)
erythromycin-treated patients. Bacteriological response was favourable (pathogen eliminated in 81 (83.5%)
dirithromycin- and 87 (87.9%)
erythromycin-treated patients. At late post-
therapy (three to five weeks
after treatment) 82/89 (92.1%)
dirithromycin- and 90/93 (96.8%)
erythromycin-treated patients had a favourable clinical response. Bacteriological response at late post-
therapy was favourable in 77 (86.5%)
dirithromycin- and 85 (94.4%)
erythromycin-treated patients. No deaths occurred during or
after treatment, and the serious events experienced by three
dirithromycin- and one
erythromycin-treated patients were unrelated to treatment. Five patients taking
dirithromycin and seven taking
erythromycin discontinued treatment prematurely, mainly due to gastrointestinal disturbances. Adverse events that occurred in 2% or more of patients in each treatment group were mainly gastrointestinal (diarrhoea,
abdominal pain,
nausea and
vomiting);
headache and
rash were also reported. No significant differences in clinical laboratory data were detected that were considered to be
drug-related.