Background: Short course antimicrobial therapy is suggested for group A streptococcal tonsillopharyngitis.
Methods: The bacteriologic and clinical efficacies of clarithromycin [30 or 15 mg/kg/day twice daily (b.i.d.)] or amoxicillin/clavulanate (43.8/6.2 mg/kg/day b.i.d.) for 5 days or penicillin V (30 mg/kg/day 3 times a day) for 10 days were compared. In a randomized, open label, parallel group, multicenter study, 626 children (2–16 years old) with tonsillopharyngitis were enrolled; 537 were evaluable for efficacy. Follow-up evaluations were performed at 4–8 and 21–28 days after therapy.
Results: At enrollment, 26% of the Streptococcus pyogenes isolates were clarithromycin-nonsusceptible. All regimens had an apparently similar clinical efficacy. The long term S. pyogenes eradication rates were 102 of 123 (83%) with amoxicillin/clavulanate and 88 of 114 (77%) with penicillin V. In the 30- and 15-mg/kg/day clarithromycin groups, eradication occurred in 71 of 86 (83%) and 59 of 80 (74%) of the clarithromycin-susceptible isolates (P = 0.33), and in 4 of 28 (14%) and 5 of 26 (19%) of the clarithromycin-resistant isolates, respectively (clarithromycin-susceptible versus -resistant, P < 0.0001). Both clarithromycin dosages were well-tolerated.
Conclusions: In group A streptococcal tonsillopharyngitis, 5 days of clarithromycin or amoxicillin/clavulanate treatment had clinical efficacy comparable with that of 10 days of penicillin V treatment; however, amoxicillin/clavulanate and penicillin V were bacteriologically more effective than clarithromycin because of its failure to eradicate the clarithromycin-resistant S. pyogenes isolates. The 5-day clarithromycin regimens are not recommended for treatment of streptococcal tonsillopharyngitis in areas where in vitro resistance of group A streptococci to clarithromycin is common.
From the *Division of Infectious Disease, Department of Pediatrics, University of Patras, Medical School, Patras, Greece; and the †Department of Pathology, Hershey Medical Center, Hershey, PA
Accepted for publication May 6, 2004.
Supported in part by a grant from Abbott Laboratories and grant 2491 from the Research Committee of the University of Patras.
Address for reprints: George A. Syrogiannopoulos, MD, Department of Pediatrics, University of Thessaly, School of Medicine, Papakyriazi 22, 412 22 Larissa, Greece. Fax 30-2410-681136; E-mail email@example.com.