title: Pharmacokinetics of lopinavir in HIV type-1-infected children taking the new tablet formulation once daily.
abstract: BACKGROUND
  Recently, a new tablet formulation of the widely used HIV protease inhibitor lopinavir/ritonavir was licensed. Here, we present a pilot study of the pharmacokinetics of the new adult tablet formulation taken once daily in children.
  
  
  METHODS
  Lopinavir pharmacokinetics of the new adult tablet formulation were evaluated in 15 HIV type-1-infected children between 4 and 15 years of age. A target dose of 460/115 mg/m2 was administered once daily. Plasma concentrations of lopinavir over the course of 24 h were determined with a validated HPLC method.
  
  
  RESULTS
  The median lopinavir dose was 498 mg/m2 (range 424-548). The mean +/- SD for lopinavir area under the 24 h curve was 217.9 +/- 44.9 mg/l x h, the maximum concentration was 14.8 +/- 2.4 mg/l and the concentration 24 h after intake was 3.1 +/- 2.6 mg/l. The half-life of lopinavir was 5.8 +/- 4.5 h and the median time to maximum concentration was 5.8 h (range 1.8-12.2). Overall, the tablet formulation resulted in greater exposure to lopinavir with less variability compared with the soft-gel capsule formulation. All children treated with the new adult tablet formulation had undetectable viral loads (< 50 copies/ml) during 24 weeks follow-up.
  
  
  CONCLUSIONS
  The tablet formulation could probably result in improved lopinavir dosing and increases the feasibility of once-daily lopinavir/ritonavir-based regimens in children.
authors.affiliation: Department of Pediatric Infectious Diseases and Immunology, Erasmus Medical Centre, Sophia Children's Hospital, Rotterdam, The Netherlands. m.vanderflier@erasmusmc.nl
authors.forename: Michiel
authors.initials: M
authors.lastname: van der Flier
authors.forename: Gwenda
authors.initials: G
authors.lastname: Verweel
authors.forename: Linda C
authors.initials: LC
authors.lastname: van der Knaap
authors.forename: Petronette
authors.initials: P
authors.lastname: van Jaarsveld
authors.forename: Gert-Jan
authors.initials: GJ
authors.lastname: Driessen
authors.forename: Manon
authors.initials: M
authors.lastname: van der Lee
authors.forename: Nico G
authors.initials: NG
authors.lastname: Hartwig
authors.forename: David M
authors.initials: DM
authors.lastname: Burger
mesh_terms: D000293:Adolescent; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D019540:Area Under Curve; D002648:Child; D002675:Child, Preschool; D004334:Drug Administration Schedule; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1 / Q000145:classification; D006207:Half-Life; D006801:Humans; D061466:Lopinavir; D008297:Male; D011744:Pyrimidinones / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D013607:Tablets
chemical_list: D019380:Anti-HIV Agents; D011744:Pyrimidinones; D013607:Tablets; D061466:Lopinavir