Previous use of amoxicillin leads to the development of urinary tract infections in children caused by resistant pathogens.

The purpose of a retrospective cohort study in Canada was to assess the effect of previous exposure to antibiotics on the development of antibiotic resistance in the first episode of urinary tract infections (UTIs) in children..

In a study from July 1, 2001 to May 31, 2006, information was analyzed on 27 pediatric outpatient sites, including information on children aged 6 months to 6 years with an initial diagnosis of UTI.

Researchers studied the relationship between the use of a number of antimicrobial agents (amoxicillin, amoxicillin / clavulanate, cefdinir, trimethoprim / sulfamethosazole and azithromycin) used in the previous episode of UTI for 120 days antibiotics of uropathogens.

Multivariate logistic regression models were used, correlated according to potential interference factors (age, number of siblings, recent hospitalizations and daycare visits).

Of the 533 children whose first episode of UTI was recorded between 6 months and 6 years, 8%, 14% and 21% were exposed to antibiotics 30, 60 and 120 days before this episode of UTI, respectively.

It has been shown that the use of amoxicillin both in previous urinary tract infections of 30 days and in the period of 31 to 60 days increases the risk of resistance of uropathogens to ampicillin by 3.6 and 2.8 times, respectively. In addition, administration of amoxicillin in the 30 days preceding a urinary tract infection also increases the risk of resistance of pathogens that cause amoxicillin / clavulunate urinary tract infection by 3.9 times. At the same time, the use of amoxicillin more than 60 days before the current episode of UTI does not lead to the development of resistance of the pathogens UTI to ampicillin. The study did not establish a link between the use of other antimicrobial agents and resistance to any of the other antibiotics studied during the study.

Thus, the recent recent use of antibiotics has led to the emergence of resistant UTIs in children on an outpatient basis, and the strength of this relationship decreases with the time that elapses after exposure to antibiotics. In this regard, physicians prescribing antibiotics on an outpatient basis should take this fact into account when making an empirical choice of antimicrobial agents for urinary tract infections, as well as adhere to the strategy of rational use of antibiotics and reduce the frequency of irrational antibiotics to avoid the development of resistance to uropathogens.