Profile of antimicrobial use and potential use of the defined daily dose in neonatology.

One of the measures for monitoring microbial resistance is the calculation of the defined daily dose of antimicrobial agents. For this calculation, the weight of an adult of 70 kg is used as a standard, so that application in neonatology is not possible. The aim of this study is to describe the use profile and calculate the defined daily dose (DDD) of antimicrobials in a neonatal intensive care unit (NICU) of a public hospital in the interior of Bahia, Brazil. From March 2020 to December 2021, the medical records of 712 newborns admitted to a NICU between September 2018 and June 2020 were analyzed. A total of 410 newborns diagnosed with neonatal sepsis were included. The most used antimicrobials per patient were gentamicin (408/410; 99.5%), ampicillin (407; 99.3%), amikacin (29; 7.1%) and oxacillin (21; 5.1%), with a mean (SD) treatment duration of 9.8 (3.9) days. The most commonly used combination of antimicrobials was ampicillin with gentamicin, which was used in 406 patients (99.0%). The values for neonatal DDDs were on average 26 times lower than those for adult DDDs. The neonatal DDDs were similar to those observed in other studies. Ampicilin and cefepime were the antimicrobials for which the greatest differences were observed in neonatal DDDs compared with adult DDDs, which differed mainly between maintenance doses, reflecting the lack of international standards in neonatology. Standardization of DDDs as a surveillance measure has the potential to clarify the pattern of antimicrobial use in neonatal patients worldwide and, in particular, to prevent indiscriminate use and bacterial resistance.