WASHINGTON — Cefdinir is superior to penicillin in eradicating group A streptococci in children with tonsillitis, Dr. Itzhak Brook and Dr. Perry A. Foote reported in a poster at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.
The failure of penicillin to eradicate group A β-hemolytic streptococci (GABHS) from inflamed tonsils, currently exceeding 40%, is of great concern. While penicillin remains effective against GABHS in vitro, several theories have been put forth to explain the high failure rate in patients, said Dr. Brook, professor of pediatrics at Georgetown University, Washington, and Dr. Foote, of the department of otorhinolaryngology at the University of Florida, Gainesville.
Data from a non-industry-funded study of 40 children aged 4–12 years who underwent elective tonsillectomy suggest that two simultaneous mechanisms may be at work: the inactivation of penicillin by β-lactamase-producing bacteria, coupled with penicillin's elimination of the “good” α-hemolytic streptococci, which interfere with the growth of GABHS, they said.
Of the children, 20 received penicillin V (17 mg/kg or 250 mg every 8 hours) while the other 20 were given cefdinir (14 mg/kg or 600 mg/day) for the 10 days prior to surgery.
After removal, GABHS was isolated from core tonsillar cultures in 11 patients in the penicillin group (55%), compared with just 3 given cefdinir (15%).
Thirty-three β-lactamase-producing bacterial organisms—predominantly Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis—were recovered from 17 (85%) of those treated with penicillin vs. 4 organisms isolated from 3 patients (15%) treated with cefdinir.
However, the penicillin patients had significantly lower numbers of α-hemolytic streptococcus, including those with the capacity to inhibit GABHS, Dr. Brook and Dr. Foote noted at the meeting, also sponsored by the American Society for Microbiology.
Adverse effects were noted in six patients, including diarrhea in two patients on penicillin and three on cefdinir, and vomiting in one of the penicillin patients.
Elsevier Global Medical News