Occurrence of Group A β-Hemolytic Streptococcal Pharyngitis in the Four Months After Treatment of an Index Episode With Amoxicillin Once-daily or Twice-daily or With Cephalexin

Abstract

Prospective studies using bacterial eradication as the endpoint have demonstrated that once-daily amoxicillin is as effective as twice-daily amoxicillin for treatment of group A β-hemolytic streptococcal (GABHS) pharyngitis. The aim of this study was to determine, in a retrospective study, whether treatment of symptomatic GABHS pharyngitis with once-daily amoxicillin was as effective in preventing clinical recurrences as twice-daily amoxicillin or cephalexin in pediatric office practice, using patient-initiated return visits for streptococcal pharyngitis as a pragmatic, clinical endpoint. The charts of consecutive patients 2 years of age and older with laboratory-proven GABHS pharyngitis for a period of 2 years were reviewed to identify index cases of streptococcal pharyngitis and subsequent episodes. Age, weight, antibiotic treatment and time from index to subsequent episodes of GABHS pharyngitis were recorded. In 1402 index episodes, patients received amoxicillin once-daily (231), amoxicillin twice-daily (846) or cephalexin (325). The risk of symptomatic streptococcal pharyngitis in the 4 months after treatment of the index episode was not statistically different among the 3 treatment groups: amoxicillin once-daily (15.1%), amoxicillin twice-daily (19.6%) and cephalexin (19.1%). There was a trend toward reduction in the risk of recurrences in the 6 weeks after completion of antibiotics in the cephalexin (9%) group compared with the combined amoxicillin (13%) groups. Amoxicillin once-daily or twice-daily was equally effective in terms of frequency of recurrence of symptomatic GABHS pharyngitis.