title: Validation of a dosage individualization table for extended-interval gentamicin in neonates.
abstract: BACKGROUND
  Extended-interval aminoglycoside dosing is increasingly used in neonates; however, guidance on how to monitor concentrations and adjust dosages accordingly is limited.
  
  
  OBJECTIVE
  To prospectively validate the use of a 22-hour gentamicin concentration dosing table for the individualization of extended-interval dosing in the neonatal population by examining the peak and trough concentrations achieved through its use.
  
  
  METHODS
  A prospective observational study was carried out on gentamicin concentrations achieved using a 22-hour post-first-dose gentamicin concentration dosing table for determining dosing intervals in neonates. Neonates (N = 104) in the first week of life, gestational age 23 weeks to full term, in level II and III neonatal intensive care units were included. Neonates were given gentamicin 5 mg/kg intravenously; a table using 22-hour post-first-dose gentamicin concentrations was then used to individualize dosing intervals. Pre- and post-serum gentamicin concentrations on the dosing interval indicated were measured with the second or third doses and used to calculate the peak and trough concentrations achieved.
  
  
  RESULTS
  Use of the 22-hour post-first-dose gentamicin concentration dosing table resulted in dosing intervals that provided appropriate peak (mean 10.55 mg/L) and trough (mean 0.75 mg/L) concentrations (with second or third doses) in all neonates. All patients had trough concentrations less than 2 mg/L, and 73% had a trough concentration less than 1 mg/L. No peak concentrations were less than 5 mg/L, 82% of patients had a peak concentration from 5 to 12 mg/L, and the remaining 18% had concentrations from 12.1 to 16 mg/L. Peak and trough concentrations were similar across all gestational ages.
  
  
  CONCLUSIONS
  Use of a 22-hour post-first-dose gentamicin concentration dosing table to individualize extended-interval gentamicin dosages in neonates resulted in appropriate peak and trough concentrations in all neonates studied. Use of this table will result in appropriate extended-interval aminoglycoside dosages in neonates early in treatment, using a single serum concentration.
authors: Pediatrics & Neonatology, Alberta Health Services, Calgary, Canada. deonne.dersch-mills@albertahealthservices.ca
authors: Deonne
authors: D
authors: Dersch-Mills
authors: Albert
authors: A
authors: Akierman
authors: Belal
authors: B
authors: Alshaikh
authors: Kamran
authors: K
authors: Yusuf
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D004334:Drug Administration Schedule; D005839:Gentamicins / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins