title: Pediatric Patients With Solid or Hematological Tumor Disease: Vancomycin Population Pharmacokinetics and Dosage Optimization.
abstract: In pediatric cancer patients, determination of optimal vancomycin dosage is essential because of high risk of inadequate concentrations and bacterial resistance. The aim of this study was to determine vancomycin pharmacokinetic parameters in this population and propose dosage optimization to achieve optimal concentration.
  
  
  
  We retrospectively reviewed the use of vancomycin in pediatric cancer patients with febrile neutropenia (hematological or solid tumor disease). Vancomycin was administered by continuous infusion, and dosages were adapted according to therapeutic drug monitoring results. Blood cultures were performed before the first dose of antibiotic. Vancomycin pharmacokinetic population parameters were determined using NONMEM software, and dosage simulations were performed according to the target concentration (20-25 mg/L).
  
  
  
  One hundred twenty-one patients were included in this study, representing 301 vancomycin concentrations. Blood cultures were positive in 37.5% of patients, and observed pathogens were mainly Staphylococcus spp. (43.8% methicillin resistant). Volume of distribution (95% confidence interval) was 34.7 L (17.3-48.0), and total apparent clearance (CL) (95% confidence interval) was correlated to body weight, tumor disease, and cyclosporine coadministration: CL = θCL × (WT/70) L/h with θCL = 3.49 (3.02-3.96), 4.66 (3.98-5.31), and 4.97 (4.42-5.41) in patients managed for hematological malignancies with or without cyclosporine coadministration and for solid malignancies, respectively. Based on simulation results, vancomycin dosage (milligram per kilogram) should be adapted to each child on the basis of its body weight and cyclosporine coadministration.
  
  
  
  Our results highlight the requirement to adapt vancomycin dosage in cancer pediatric population. Simulations have allowed to describe new dosage schedules, and a chart was created for clinicians to adapt vancomycin dosage.
authors.affiliation: *Service de Pharmacologie Clinique et Pharmacovigilance, Hôpital de la Timone; †Pharmacologie Intégrée Interface Clinique et Industriel, Institut des Neurosciences Timone; ‡Service d'Hématologie et Oncologie Pédiatrique, Hôpital de la Timone; §Service de Pharmacologie Clinique, Centre Anti-Poison, Hôpital Sainte Marguerite; ¶Aix-Marseille Université; and ‖Aix-Marseille Université, Inserm, SESSTIM UMR_S 912, Marseille, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Guilhaumou
authors.forename: Amélie
authors.initials: A
authors.lastname: Marsot
authors.forename: Julien
authors.initials: J
authors.lastname: Dupouey
authors.forename: Claire
authors.initials: C
authors.lastname: Galambrun
authors.forename: Audrey
authors.initials: A
authors.lastname: Boulamery
authors.forename: Carole
authors.initials: C
authors.lastname: Coze
authors.forename: Nicolas
authors.initials: N
authors.lastname: Simon
authors.forename: Nicolas
authors.initials: N
authors.lastname: André
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D002648:Child; D016572:Cyclosporine / Q000008:administration & dosage / Q000627:therapeutic use; D054796:Drug Dosage Calculations; D016903:Drug Monitoring; D004359:Drug Therapy, Combination; D064147:Febrile Neutropenia / Q000097:blood / Q000150:complications / Q000188:drug therapy; D005260:Female; D019337:Hematologic Neoplasms / Q000097:blood* / Q000150:complications; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008954:Models, Biological; D009369:Neoplasms / Q000097:blood* / Q000150:complications; D012189:Retrospective Studies; D014640:Vancomycin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D016572:Cyclosporine