For kids, 2 antibiotics aren’t better than 1

JOHNS HOPKINS (US) — One antibiotic is just as likely as two to beat a child’s invasive bloodstream infection, but at less than half the risk of drug-induced kidney damage, a new study shows.

The finding challenges the common practice of preemptively and liberally prescribing combination drug treatments for children with bloodstream infections.

“Many pediatricians continue to prescribe combination-drug regimens under the false assumption that two is better than one, but our study suggests otherwise,” says Pranita Tamma, an infectious disease specialist at Johns Hopkins University. “One is often just as good as two—and a lot safer.”


The two-drug regimen includes a class of antibiotics known as aminoglycosides, well-known for their toxic effects on the kidney. The benefit of using those drugs may outweigh the risks in critically ill patients or those suspected to be infected with highly drug-resistant organisms.

But researchers say that even then, the need for continued dual therapy should be assessed as soon as bacterial cultures reveal what antibiotics are effective against the infectious organisms. The results of those tests are usually available within 48 to 72 hours of diagnosis.

“The aminoglycoside portion of the regimen should be continued only in cases of highly drug-resistant infections,” Tamma says.

For the study, published in JAMA Pediatrics, researchers reviewed 879 cases of children treated at Johns Hopkins Children’s Center between 2002 and 2011 for bloodstream infections caused by a group of pathogens collectively known as Gram-negative bacteria.

Gram-negative organisms encompass more than 80 types of infection-causing bacteria, including bacteria that commonly live in the gut, such as E. coli.

Of the 879 patients, 537 (61 percent) received combination treatment. Those on dual and single treatment had similar risks of death, with 7.6 percent of patients in combo therapy dying, compared with 6.7 percent in the single-drug group.

Patients who got the combo therapy, however, were more than twice as likely to suffer kidney damage: One-quarter of those on the dual-antibiotic regimen developed kidney damage, compared with 10 percent of those getting the single-drug treatment.

The Thomas Wilson Sanitarium for Children of Baltimore City and by the National Institutes of Health funded the study. Other researchers from Johns Hopkins and the University of Maryland contributed to the report.

Source: Johns Hopkins University