Nafcillin Therapy a Safe Alternative to Vancomycin for Infants With Late-Onset Sepsis

By Brandon May

April 18, 2022

NEW YORK (Reuters Health) - Nafcillin is safe when used as empirical treatment for late-onset sepsis (LOS) in infants in the neonatal intensive-care unit (NICU) who don't have a history of methicillin-resistant Staphylococcus aureus infection or colonization, and the drug may be considered a safe alternative to vancomycin for these infants, researchers say.

"Vancomycin, in combination with an aminoglycoside, has been recommended for empirical treatment of late-onset sepsis in NICUs, as coagulase-negative staphylococci remain the most frequent bloodstream pathogens," Dr. Jacqueline Magers of Nationwide Children's Hospital, in Columbus, Ohio, and colleagues write in Pediatrics. "Concern exists for development of vancomycin resistance from its overuse."

In 2014, the Neonatal Antimicrobial Stewardship Program team at Nationwide Children's recommended nafcillin instead of vancomycin, in combination with gentamicin, for empirical treatment of possible LOS in NICU infants who did not have a history of methicillin-resistant S. aureus colonization or infection.

To evaluate the safety of this recommendation, Dr. Magers and colleagues conducted a retrospective review of infants from three NICUs receiving nafcillin or vancomycin for empirical treatment of possible LOS both prior to and following the implementation of the vancomycin-reduction guideline.

The cohort included a total of 366 infants who received a first antibiotic course for possible LOS. About 84% of these infants received empirical therapy with vancomycin before the guideline implementation, and 25% received empirical therapy with vancomycin after the guideline implementation, a 70% drop. In contrast, the use of nafcillin increased by 368% following the guideline implementation.

There was no difference in the duration of blood culture positivity before and after the guidance. Antibiotic therapy was resumed in two infants within 14 days of discontinuation of the initial treatment for recurrence of the same infection. Each of the infants had been treated with empirical vancomycin.

There was no significant difference in the overall rate of in-hospital mortality between the periods before and after implementation of the vancomycin-reduction guidance (9% vs. 10%, respectively).

"There are several antibiotics effective at eradicating S. aureus, but there are patient-specific and public-health implications when not using the most optimal antibiotic," Dr. Magers told Reuters Health by email.

"Clinical implications of using nafcillin and 'judicious vancomycin' is preventing or slowing down the development of resistant bacteria," she said.

Dr. Magers also noted that vancomycin is associated with serious side effects, such as nephrotoxicity. Using nafcillin instead may reduce the incidence of acute kidney injure, and may also lead to fewer blood draws, given that nafcillin therapy is not typically guided by drug levels.

The researchers report no conflicts of interest or study funding.

SOURCE: Pediatrics, online April 5, 2022.