Antimicrobial defined daily dose in neonatal population

Background: Antimicrobial defined daily dose (DDD), a standardized metric to assess antimicrobial con-sumption in adult population, has limitations hampering its use in neonatal patients. This study proposes an alternative DDD design applicable for neonates. Methods: Neonates (<1 month-old) from 6 Spanish hospitals during a 12-months period were included. Weight and weeks gestational age of each neonate were the variables collected. DDD (g) for each antimi-crobial was calculated by multiplying the obtained weight times the recommended dose (mg/kg) of the antimicrobial for the most common infectious indication selected by the Delphi method. Results: A total of 4820 neonates were included. Mean age was 36.72 weeks of gestational age and Mean weight was 2.687 kg. Standardized DDD (intravenous; oral route) for representative antimicrobials were: Amoxicillin (0.08; 0.08), amoxicillin-clavulanic acid (0.27; 0.08), ampicillin (0.27; x), cloxacillin (0.13; 0.13), penicillin G sodium (0.12), cefazolin (0.13), cefuroxime (0.27; x), cefotaxime (0.27), cef-tazidime (0.27), ceftriaxone (0.13), cefepime (0.27) piperacillin-tazobactam (0.54), aztreonam (0.24), azithromycin (0.03; 0.03), clindamycin (0.04; 0.04), amikacin (0.04), gentamicin (0.01), metronidazole (0.04; 0.08), ciprofloxacin (0.04; 0.05), levofloxacin (x;x), fluconazole (0.02; 0.02), itraconazole (0.01; 0.01), fosfomycin (0.27). Restricted antimicrobials: meropenem (0.11), teicoplanin (0.02), vancomycin (0.08; 0.11), linezolid (0.08; 0.08), daptomycin (x), amphotericin B liposomal (0.01). Conclusions: A useful method for antimicrobial DDD measurement in neonatology has been designed to monitor antimicrobial consumption in hospital settings. It should be validated in further studies and thereby included in the design for neonatal antimicrobial stewardship programs in the future.