Evaluation of the efficacy, safety and toleration of azithromycin vs. penicillin V in the treatment of acute streptococcal pharyngitis in children: results of a multicenter, open comparative study. The Swiss Tonsillopharyngitis Study Group.

Background: For many years alternatives to penicillin have been studied for the management of pediatric group A beta-hemolytic Streptococcus (GABHS) pharyngitis. As a result of its pharmacokinetic profile azithromycin is unique among these alternative antimicrobials in allowing once daily dosing and shorter duration of treatment. However, the optimum dose (e.g. 10 or 12 mg/kg/day) and duration (e.g. 3 or 5 days) of azithromycin therapy have not been defined yet.

Methods: An open, comparative multicenter study was conducted in 343 children with clinical symptoms of GABHS pharyngitis and a positive culture to evaluate the efficacy and safety of azithromycin (10 mg/kg) once daily for 3 days compared with penicillin V three times daily for 10 days.

Results: Among the evaluable patients bacteriologic eradication documented at follow-up visits was inferior with azithromycin when compared with penicillin V therapy: at Days 9 to 20 (mean, 12 days), negative cultures in 65% (99 of 152 patients) vs. 82% (128 of 126 patients) (P < 0.001); and at Days 17 to 57 (mean, 25 days), in 55% vs. 80% (P < 0.001). Overall clinical success (cure or improvement) was achieved in 93% (149 of 160 patients) of azithromycin-treated and in 89% (143 of 160 patients) of penicillin-treated patients (P > 0.50). There was no correlation between bacteriologic response and clinical outcome, as assessed shortly after completion of therapy or during 6-month follow-up. Both treatments were well-tolerated.

Conclusions: In the present study on GABHS pharyngitis in children, a once daily (10-mg/kg), 3-day oral regimen of azithromycin was as clinically effective and as safe as traditional penicillin but appeared inferior in eliminating GABHS from the throat.