Twice-a-day regimen of erythromycin base is effective in the treatment of acute streptococcal tonsillitis.

A multicenter clinical trial on the efficacy and safety of a twice-a-day administration of erythromycin base was performed on 261 adolescent or adult patients with acute tonsillitis. The patients were randomized for each doctor separately into q.i.d. (4 x 250 mg) and b.i.d. (2 x 500 mg) groups. Throat swabs were cultured for group A beta-haemolytic streptococci before the treatment and, in positive cases (100 patients), 2-3 days after completing the treatment of at least 7 days. No significant difference in the efficacy between the two regimens was observed as judged by clinical evaluation or bacteriological examination. About 90% of patients were completely healed by both criteria in both treatment groups. Side-effects were reported in 40 and 44% respectively, in the treatment groups. However, only 9/244 (3.7%) had to stop the treatment because of side-effects. Six of these belonged to the b.i.d. group and 3 to the q.i.d. group. This difference is not statistically significant (p greater than or equal to 0.05). Our results suggest that twice-a-day regimen of erythromycin base is an effective and well-tolerated treatment of streptococcal tonsillitis.