[Treatment of streptococcal tonsillitis with once-a-day amoxicillin: a meta-analysis].

INTRODUCTION: The objective of this systematic review is to determine if the treatment of streptococcal pharyngitis with a daily dose of amoxicillin is similar in effectiveness to other dosing schedules (every 6, 8 or 12 hours) of the same antibiotic or penicillin V. MATERIAL AND METHODS: Randomised clinical trials (RCT) comparing amoxicillin (one dose per day) compared to other dosages of amoxicillin (every 8-12 hours) or penicillin V (every 6, 8 or 12 hours). Search databases consulted: Medline, Central, EMBASE and Google Scholar. The results were combined using the risk difference (RD). We measured the effectiveness of each treatment with a negative throat culture on the 14-21th day, being previously positive to group A Streptococcus (under a non-inferiority hypothesis, where the upper limit of the 95% confidence interval [95% CI] of the DR does not exceed 10%) and clinical failure on days 10-21. The results were combined according to a fixed effects model or random depending on whether or not there was heterogeneity. RESULTS: Four RCT met the selection criteria with 1,314 participants (657 received amoxicillin once per day, and 657 received other antibiotics or dosages): a) any positive culture for Streptococcus (14-21st day, 4 RCTs): DR: -0.5% (95% CI: -5.1% to 4.2%; b) persistence of the same serotype (14-21st day, 3 RCT): DR: 0.32% (95% CI: -3.1% to 3.7%; c) clinical failure (2 RCT): DR: 1.7% (95% CI: -1.9% to 5.4%; d) adverse effects (4 RCT): DR: -0.39% (95% CI: -1.5% to 6.8%). There were no statistically significant differences in any comparisons. CONCLUSIONS: Amoxicillin, administered once daily is not inferior to other dosages of the same antibiotic or penicillin V. These results are important because they may facilitate compliance.