title: Extended-interval gentamicin dosing in achieving therapeutic concentrations in malaysian neonates.
abstract: OBJECTIVE
  To evaluate the usefulness of extended-interval gentamicin dosing practiced in neonatal intensive care unit (NICU) and special care nursery (SCN) of a Malaysian hospital.
  
  
  METHODS
  Cross-sectional observational study with pharmacokinetic analysis of all patients aged ≤28 days who received gentamicin treatment in NICU/SCN. Subjects received dosing according to a regimen modified from an Australian-based pediatric guideline. During a study period of 3 months, subjects were evaluated for gestational age, body weight, serum creatinine concentration, gentamicin dose/interval, serum peak and trough concentrations, and pharmacokinetic parameters. Descriptive percentages were used to determine the overall dosing accuracy, while analysis of variance (ANOVA) was conducted to compare the accuracy rates among different gestational ages. Pharmacokinetic profile among different gestational age and body weight groups were compared by using ANOVA.
  
  
  RESULTS
  Of the 113 subjects included, 82.3% (n = 93) achieved therapeutic concentrations at the first drug-monitoring assessment. There was no significant difference found between the percentage of term neonates who achieved therapeutic concentrations and the premature group (87.1% vs. 74.4%), p = 0.085. A total of 112 subjects (99.1%) achieved desired therapeutic trough concentration of <2 mg/L. Mean gentamicin peak concentration was 8.52 mg/L (95% confidence interval [Cl], 8.13-8.90 mg/L) and trough concentration was 0.54 mg/L (95% CI, 0.48-0.60 mg/L). Mean volume of distribution, half-life, and elimination rate were 0.65 L/kg (95% CI, 0.62-0.68 L/kg), 6.96 hours (95% CI, 6.52-7.40 hours), and 0.11 hour(-1) (95% CI, 0.10-0.11 hour(-1)), respectively.
  
  
  CONCLUSIONS
  The larger percentage of subjects attaining therapeutic range with extended-interval gentamicin dosing suggests that this regimen is appropriate and can be safely used among Malaysian neonates.
authors.affiliation: Department of Pharmacy, Sultanah Fatimah Specialist Hospital, Muar, Johor.
authors.forename: Yee Shan
authors.initials: YS
authors.lastname: Low
authors.affiliation: Department of Pharmacy, Sultanah Fatimah Specialist Hospital, Muar, Johor.
authors.forename: Sin Li
authors.initials: SL
authors.lastname: Tan
authors.affiliation: Department of Pediatrics, Sultanah Fatimah Specialist Hospital, Muar, Johor.
authors.forename: Angeline Sl
authors.initials: AS
authors.lastname: Wan
keywords: aminoglycosides; extended-interval; gentamicin; neonate; pharmacokinetics