RANDOMIZED, SINGLE-BLINDED COMPARATIVE-STUDY OF THE EFFICACY OF AMOXICILLIN (40 MG KG/DAY) VERSUS STANDARD-DOSE PENICILLIN-V IN THE TREATMENT OF GROUP-A STREPTOCOCCAL PHARYNGITIS IN CHILDREN/

A 10-day course of amoxicillin at a dosage of 40 mg per kilogram per d ay was compared with conventional (lower dosage) penicillin V therapy in the treatment of culture-proven Group A streptococcal pharyngitis i n children 3 to 18 years of age in a prospective, randomized, and sing le-blinded study. Children had to have signs and symptoms compatible w ith the diagnosis of streptococcal pharyngitis and to have a throat sw ab positive for Group A streptococci. A second throat culture was obta ined 10 to 14 days after the completion of therapy Serotyping tvas per formed to help differentiate carrier states from reinfections. Of 161 children enrolled, 113 were evaluable; 55 received penicillin and 58 r eceived amoxicillin. At the completion of therapy 70.9% (39/55) of pat ients in the penicillin group vs 87.9% (51/58) of patients in the amox icillin group were asymptomatic (clinical cure, P=0.025). At the compl etion of therapy, 54.5% (30/55) of patients in the penicillin group vs 79.3% (46/58) of patients in the amoxicillin group had negative throa t cultures (bacteriologic cure, P=0.005). The carrier rate (children w ho were well but who were still carrying the same serotype of Group A streptococcus) also differed betweent the groups: 13 (23.6%) in the pe nicillin group compared with six (10.3%) in the amoxicillin group. Amo xicillin at 40 mg/kg/day was significantly more effective than lower d osages of penicillin V for clinical and bacteriologic cure in the trea tment of Group A streptococcal pharyngitis in children. The current pe rception that penicillin is declining in effectiveness may be due to i nadequate dosing.