Antimicrobials slash rate of recurring UTIs

Antibiotic prophylaxis with trimethoprim/sulfamethoxazole (TMP/SMZ) significantly reduces the risk of recurrence of urinary tract infection (UTI) in children with vesicoureteral reflux (VUR) after UTI, but does not reduce the risk of renal scarring, according to a randomized, placebo-controlled trial.

The study is the first to provide clinical evidence of the effectiveness of the long-held practice of treating kids with VUR with a small daily dose of TMP/SMZ, sometimes for years, in the hope of preventing kidney damage.

In a 2-year, multisite trial called the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial, investigators from 19 locations around the country studied 607 children aged younger than 6 years with VUR diagnosed after a first or second febrile or symptomatic UTI. Most (91.9%) of the participants were girls, and the median age was 12 months.

Data showed UTI recurred in about half as many children who received the antimicrobial combination compared with those who received placebo (39 of 302 vs 72 of 305, respectively; relative risk, 0.55; 95% confidence interval, 0.38-0.78). The greatest benefit occurred in children with bladder and bowel dysfunction. Kids treated with the combination antibiotic had up to an 80% lower risk of recurrent infection.

However, the occurrence of scarring did not differ significantly between the groups (11.9% of the prophylaxis group vs 10.2% of the placebo group).

The researchers did notice some antibiotic resistance. Of 87 children with a first recurrence UTI caused by Escherichia coli, almost two-thirds (63%) of isolates from the children receiving the drugs were resistant to TMP/SMZ, as were 19% in the placebo group.

The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases. According to the National Institutes of Health, VUR affects about 30% to 40% of children who develop a UTI. 

To get weekly clinical advice for today's pediatrician, subscribe to the Contemporary Pediatrics eConsult.