Article Text

Download PDFPDF

NP-019 Development of a conversion factor between defined daily doses of adults and neonates
  1. C Villanueva Bueno,
  2. MV Gil Navarro1,
  3. E Montecatine Alonso1,
  4. F Jiménez Parrilla2,
  5. MJ Cabañas Poy3,
  6. M González López4,
  7. C Martínez Fernández Llamazares5,
  8. OW Neth6
  1. 1Department of Pharmacy, Institute of Biomedicine of Seville (IBIS), Hospital Universitario Virgen del Rocío, Sevilla, Spain
  2. 2Department of Neonatology Hospital Universitario Virgen del Rocío, Sevilla, Spain
  3. 3Department of Pharmacy, Hospital Universitario Vall d’Hebron, Barcelona, Spain
  4. 4Department of Neonatology, Hospital Materno-Infantil Regional de Málaga, Málaga, Spain
  5. 5Department of Pharmacy, Hospital Gregorio Marañón. Instituto de Investigación Sanitaria Gregorio Marañón.Madrid, Spain
  6. 6Paediatric Infectious Diseases, Rheumatology and Immunology Unit, Hospital Universitario Virgen del Rocío, Sevilla, Institute of Biomedicine of Seville (IBIS), Spain


Background and importance Absence of a standardised method to measure antimicrobial consumption in the neonatal population

Aim and objectives Establish a conversion factor that makes possible to relate the defined daily dose (DDD) of the adult population and the DDD of the neonatal population.

Materials and methods National, multicentre and retrospective study. It had the participation of 10 third-second level hospitals and a multidisciplinary team: hospital pharmacists, paediatricians, neonatologists and infectious disease experts.

First, after selecting the antimicrobials for study based on the literature and routine clinical practice, the Delphi methodology was used to agree on the recommended dose for its most common indication in the neonatal population. Two rounds of consultation with the group of experts were carried out. For those antimicrobials whose dose was not agreed upon, the dose established in Pediamecum was selected.

The weight and gestational age of the neonates (<1 month) admitted to 6 hospitals during 2018 were collected through the admission records or own records of the pharmacy or neonatology services of these hospitals. The mean, median, standard deviation and maximum and minimum of each of the variables were calculated.

Subsequently, the DDD in grams of each antimicrobial were calculated.

Finally, the conversion factor was obtained by comparing the DDD designed for neonates (DDDn) with the DDD validated by the WHO for adults (DDDa).

For the analysis of the results, the statistical package IBM SPSS Statistics version 19 was used.

Results 4820 neonates were selected. The mean weight was 2687 g(6080–440).

The conversion factor (DDDn/DDDa) of the parenterally administered antimicrobials were: amikacin (0.04), amoxicillin (0.03), amoxicillin-clavulanate (0.09), ampicillin (0.04), liposomal amphotericin B (0.38), azithromycin (0.05), aztreonam (0.06), cefazolin (0.04), cefepime (0.07), cefotaxime (0.07), ceftazidime (0.07), ceftriaxone (0.07), ciprofloxacin(0.05), erythromycin(0.13), fluconazole(0.08), gentamicin (0.04), imipenem-cilastatin (0.07), linezolid (0.07), meropenem (0.04), metronidazole (0.03), micafungin (0.05), penicillin G sodium (0.03), piperacillin-tazobactam (0.04), teicoplanin (0.04), and vancomycin (0.04)

Those obtained from oral antimicrobials were: amoxicillin (0.05), amoxicillin-clavulanate (0.08), azithromycin (0.09), cefadrozil (0.04), cefixime (0.05), ciprofloxacin (0.05), clindamycin (0.03), cloxacillin (0.07), erythromycin (0.13), fluconazole (0.08), Fosfomycin (0.09), itraconazole (0.04), linezolid (0.07), metronidazole (0.04) and vancomycin (0.05).

Conclusion and relevance Analysing the demographic characteristics of the neonatal population, the DDD of the antimicrobial group can be standardised, this allows establishing a conversion factor with respect to the adult DDD. A new study to confirm the validity of designed neonatal DDD and hence the conversion factor between neonatal DDD and adult DDD is underway.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.