An adult hand syringes red liquid medicine into a baby’s mouth. The baby is looking at the caregiver and clutching a pink toy.
Research and Breakthroughs

Which Antibiotics Best Prevent Infections for Children With Vesicoureteral Reflux?

Study identifies antibiotic resistance trends in Los Angeles for patients with reflux who are on continuous antibiotic therapy.
Headshot of a smiling man with light skin tone and short, light brown hair wearing a white dress shirt and orange and blue striped tie under a grey suit jacket against a blurred outdoor background
Scott Sparks, MD

Children with vesicoureteral reflux often need to take continuous antibiotics to reduce the risk of urinary tract infections (UTIs). But which antibiotics do the best job at preventing these infections?

Researchers in the Division of Urology at Children’s Hospital Los Angeles recently conducted a study to shed more light on this issue. The results were presented in September at the Societies for Pediatric Urology Fall Congress in Houston.

“This is a complex question because we know that antibiotic resistance patterns are variable, based on region and many other factors,” says Scott Sparks, MD, a pediatric urologist at CHLA who led the study. “We wanted to see if we could identify any definitive trends about antibiotic effectiveness for our patients here in Los Angeles.”

Key findings

Vesicoureteral reflux is typically a congenital condition in which urine flows backward from the bladder to the ureters or kidneys. Reflux commonly resolves on its own as children grow. But until that happens, some patients may benefit from continuous low-dose antibiotic therapy to prevent UTIs.

The retrospective study examined how often these patients have breakthrough UTIs. The study included 402 children with reflux who were seen at CHLA from 2015 to 2021. All the patients were on continuous antibiotic therapy.

The study found that:

  • Patients taking cephalexin had the highest rates of breakthrough UTIs, at 2.52 per 100 person months.
  • Patients taking sulfamethoxazole/trimethoprim also had relatively high rates of infections, at 1.52 per 100 person months.
  • A large percentage of breakthrough UTIs were resistant to both cephalexin and sulfamethoxazole/trimethoprim.
  • Nitrofurantoin had the lowest rates of breakthrough UTIs.

Guiding discussions with families

Dr. Sparks cautions that these findings are specific to the Los Angeles area. Breakthrough rates are also just one factor in deciding on the best antibiotic for a particular patient.

For example, while nitrofurantoin had the lowest rates of infections, it can be difficult for parents to administer. The medicine does not come in a liquid, and because patients with reflux are typically very young, capsules must be opened up and sprinkled on food.

“I think the biggest take-home message is that, while there’s no perfect choice, it’s important for physicians to be aware of the antibiotic resistance patterns in their own community,” Dr. Sparks says.

“I haven’t significantly changed my prescribing patterns based on these findings,” he adds. “But it has helped me have better discussions with families. I can give them more specific data now about each medicine and what they can expect. Then together, we can make the best choice for each child.”

Study authors were Zoë Baker, PhD; Helal Syed, MD; and Scott Sparks, MD.

Learn more about pediatric urology at Children’s Hospital Los Angeles.