Six-day amoxicillin vs. ten-day penicillin V therapy for group A streptococcal tonsillopharyngitis.

Objective: To compare the efficacy and safety of amoxicillin (50 mg/kg/day divided twice daily) for 6 days and penicillin V (45 mg/kg/day divided into three doses/day) for 10 days in children with group A streptococcal (GAS) tonsillopharyngitis.

Methods: In a prospective, comparative, open, randomized, multicenter trial, children were scheduled to return for visits 4 days (main end point) and 1 month after the completion of treatment for clinical and bacteriologic assessment. Total DNA restriction fragment length polymorphism was used to compare pre- and posttreatment GAS isolates.

Results: Between September, 1993, and February, 1995, 321 children (161 amoxicillin, 160 penicillin V) were enrolled, among whom 318 (160 amoxicillin, 158 penicillin V) were evaluable for safety, and 277 were evaluable for efficacy. Four days after the completion of treatment, pretreatment GAS were eradicated from 118 of the 141 children receiving amoxicillin (83.7%) and 116 of the 136 (85.3%) taking penicillin. One month after the outset of treatment, bacteriologic relapses were observed in 9.9% (n = 11) of the children receiving amoxicillin and 5.7% (n = 6) of those treated with penicillin V, bacteriologic recurrences in 5 and 3 patients, respectively. Adverse events related to the study medications were reported in 4 patients in the amoxicillin group and 8 in the penicillin V group. Drug-related adverse events leading to treatment discontinuation occurred in 3 patients, all in the penicillin V group. Compliance, based on diary cards and the weight of study drugs returned, was significantly better in the amoxicillin group. CONCLUSIONS. The efficacy and safety of amoxicillin (50 mg/kg/day twice daily) for 6 days were not statistically different from those of penicillin (45 mg/kg/d three times a day) for 10 days in the treatment of GAS tonsillopharyngitis.