Some VUR patients can safely stop antibiotics

San Francisco-Selected children with persistent vesicoureteral reflux can safely discontinue prophylactic antibiotics without a significant risk of upper tract infections or new renal scarring, according to results of a retrospective Canadian study.

Nine of 78 children developed infection after discontinuation, but five continued off antibiotics with no new infections. No patient developed new renal scarring, according to the study's authors, who presented the data at the American Academy of Pediatrics Section on Urology meeting here.

"Discontinuing prophylactic antibiotics in selected school-aged children with persistent VUR is a safe practice," said Ahmed J. Al-Sayyad, MD, a urology resident at Children's Hospital of Eastern Ontario in Ottawa, who worked on the study under associate professor Michael P. Leonard, MD. "The risk of significant upper tract infection is low. The development of new renal scars is unlikely. Continuing surveillance of these children by their family doctor and urologist is necessary."

The risk of renal scarring with infection is greatest in children younger than 1 year of age, Dr. Al-Sayyad said. Patients who have a febrile upper tract infection before 4 years of age have a greater likelihood of scarring than older children. Prompt treatment of pyelonephritis prevents renal scar formation.

Investigators in two previous studies have evaluated the safety of discontinuing antibiotics in children with VUR. In one study, 51 refluxing patients were taken off antibiotics and followed for an average of 3.7 years (J Urol 2000; 163:269-72). During follow-up, five patients had pyelonephritis, and one had cystitis. All infections were treated without the development of new renal scarring. The investigators concluded that stopping antibiotics is reasonable in highly selected patients with VUR.

A second study involved 196 refluxing patients off antibiotics (J Urol 2001; 166:1465-9). While on antibiotic prophylaxis, the patients had a rate of upper tract infection of 0.29/year, compared with 0.24/year when they were off antibiotics. New renal scarring developed in 2.2% of boys and 4% of girls.

In the most recent study, Dr. Al-Sayyad and colleagues retrospectively reviewed 78 VUR patients (67 girls and 11 boys) who discontinued antibiotic prophylaxis. Patients were at least 4 years of age, except for 10 younger patients whose parents elected to stop antibiotics. Outcome measures included age at the time of stopping antibiotics, duration on and off antibiotics, grade of reflux at the time of stopping antibiotics, occurrence of urinary tract infections, and development of new renal scarring with follow-up.

All patients had upper tract assessment by interval renal ultrasound. Most patients also had nuclear cystograms to follow reflux status. Reflux was bilateral in 46%, unilateral left side in 37%, and unilateral right side in 17%. Three-fourths of the patients (72.2%) had grade II reflux at the time of antibiotic cessation, and 7.7% had grade III reflux. The remainder had grade I VUR.

Mean age at discontinuation of antibiotics was 5.74 years (range, 1 to 12 years). The patients had been on antibiotic prophylaxis for an average of 26.29 months (range, 0 to 84 months). Time off antibiotics ranged between 5 and 138 months and averaged 37.73 months.

All nine of the patients who developed urinary tract infections were girls. The infections were cystitis in eight cases and pyelonephritis in one. The infections occurred in four patients who had bilateral reflux and in five who had left-sided reflux. Reflux was grade II in eight cases and grade I in the remaining case. The period off antibiotics for the patients who developed infections averaged 21.1 months and ranged between 5 and 60 months.

"None of our patients, including those with UTI, developed new scarring of their kidneys as detected by serial renal ultrasound," Dr. Al-Sayyad said. "The patient who had pyelonephritis had a DMSA [dimercaptosuccinic acid] scan, which was negative."