title: Nelfinavir pharmacokinetics in stable human immunodeficiency virus-positive children: Pediatric AIDS Clinical Trials Group Protocol 377.
abstract: OBJECTIVE
  Pharmacokinetic data obtained from children who have human immunodeficiency virus (HIV) infection are essential for the safe and effective use of antiretroviral agents in pediatric populations. The objective of this study was to assess the impact of body weight on the pharmacokinetic disposition of nelfinavir (NFV) in the absence and presence of nevirapine (NVP) and compare the pharmacokinetic profiles of twice-daily (BID) and three-times-daily (TID) NFV regimens.
  
  
  METHODS
  This was an intensive pharmacokinetic substudy nested in a phase II, multicenter, randomized, open-label trial. Forty-five HIV-infected children receiving NFV 30 mg/kg TID and 6 HIV-infected children receiving NFV 55 mg/kg BID were enrolled in this study and assigned to 1 of 4 stavudine-containing regimens, 3 containing NFV and 2 containing NVP. Area under the plasma concentration-time curves from 0 to 8 hours (AUC(0-8 hours)) and from 0 to 12 hours (AUC(0-12 hours)) for the TID and BID regimens, respectively, were determined. For comparative purposes, the AUC(0-24 hours) was also calculated for each regimen.
  
  
  RESULTS
  NFV exposure in the absence of NVP was decreased in children who were <25 kg compared with those who were >25 kg (a 2.6-fold difference in median AUC(0-8 hours)). NFV pharmacokinetics in the presence of NVP did not differ between the <25 kg and >25 kg groups. The AUC(0-24 hours) for children who were <30 kg and on NFV BID was comparable to the AUC(0-24 hours) for children who were >25 kg and on NFV TID but was 2.7-fold greater than AUC(0-24 hours) for children who were <25 kg and on NFV TID.
  
  
  CONCLUSIONS
  NFV in the absence of NVP resulted in less than half the drug exposure in children who were <25 kg compared with children who were >25 kg. NFV dosed at 55 mg/kg BID in children who are <30 kg provides comparable exposure to that measured in children who are >25 kg and receiving NFV 30 mg/kg TID.
authors.affiliation: Drug Research Unit, Department of Clinical Pharmacy, University of California, San Francisco, California, USA.
authors.forename: Leslie Carstensen
authors.initials: LC
authors.lastname: Floren
authors.forename: Andrew
authors.initials: A
authors.lastname: Wiznia
authors.forename: Sandra
authors.initials: S
authors.lastname: Hayashi
authors.forename: Anura
authors.initials: A
authors.lastname: Jayewardene
authors.forename: Kenneth
authors.initials: K
authors.lastname: Stanley
authors.forename: George
authors.initials: G
authors.lastname: Johnson
authors.forename: Sharon
authors.initials: S
authors.lastname: Nachman
authors.forename: Paul
authors.initials: P
authors.lastname: Krogstad
authors.forename: Francesca T
authors.initials: FT
authors.lastname: Aweeka
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy*; D000293:Adolescent; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods; D001682:Biological Availability; D001835:Body Weight / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D004304:Dosage Forms; D004334:Drug Administration Schedule; D017320:HIV Protease Inhibitors / Q000493:pharmacokinetics / Q000627:therapeutic use; D015497:HIV-1 / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D019888:Nelfinavir / Q000493:pharmacokinetics* / Q000627:therapeutic use; D019829:Nevirapine / Q000627:therapeutic use
chemical_list: D004304:Dosage Forms; D017320:HIV Protease Inhibitors; D019829:Nevirapine; D019888:Nelfinavir