Trial finds modest reductions in kidney injury and death with cefazolin or benzylpenicillin versus flucloxacillin for staph bloodstream infections

An international clinical trial led by the Doherty Institute in Melbourne found that cefazolin and benzylpenicillin produced lower rates of acute kidney damage and death than flucloxacillin when treating Staphylococcus aureus bacteraemia, commonly called golden staph bloodstream infections.

The study randomly assigned patients admitted to more than 150 hospitals in 14 countries, including Australia, the United States and the United Kingdom, to receive either flucloxacillin or one of the two alternatives. Researchers tracked outcomes over 90 days.

In the cefazolin comparison, 20 per cent of patients given flucloxacillin developed acute kidney damage, compared with 14 per cent of those given cefazolin. Mortality within 90 days was 17 per cent for flucloxacillin and 15 per cent for cefazolin. In the benzylpenicillin comparison, 22 per cent of patients on flucloxacillin died within 90 days, compared with 14 per cent on benzylpenicillin.

The findings were published in The Lancet and the New England Journal of Medicine. Professor Steven Tong, an infectious diseases physician at the Doherty Institute and global co-lead investigator of the cefazolin study, said the results had already altered his practice.

“I reflected what most Australian infectious disease physicians used to do, which was to use flucloxacillin in most cases, but now I have completely switched,” he said.

Tong added that the lower mortality rate with cefazolin surprised the researchers. “To actually see that people were less likely to die when they got cefazolin surprised all of us,” he said. At the Royal Melbourne Hospital, where Tong works, two cases of serious golden staph bloodstream infections occur each week.