title: Extended-release divalproex in child and adolescent outpatients with epilepsy.
abstract: OBJECTIVE
  To determine whether valproic acid [divalproex (DVP)] extended-release, administered at a higher proportionate once-daily dosage, can be safely substituted for delayed-release or sprinkle in pediatric patients with epilepsy.
  
  
  METHODS
  Patients between ages 6 and 17 years with stable epilepsy taking DVP were randomized to 7 days of either DVP delayed-release/sprinkle (at the usual daily dose taken before study entry) or extended-release DVP (daily dose, 8% to 25% higher than their usual dose), and then (crossed over to) 7 days of the comparator formulation. Patient's clinical status was evaluated at a screening visit and on days 8 and 15, and with telephone follow-up 1 month after study completion.
  
  
  RESULTS
  No statistically significant difference in mean plasma VPA levels measured at the end of treatment was observed: 99, 92, and 103 mug/ml with the delayed-release tablets (n = 4), the sprinkle formulation (n = 11), and the extended-release tablets (n = 16), respectively. Seizure-control rates were stable during patients' use of the extended-release formulation. None of the study patients experienced a treatment-related adverse event.
  
  
  CONCLUSIONS
  The total daily dose for patients taking the delayed-formulation may need to be increased by < or = 20% when they are switched to the extended-release formulation. When switching from sprinkles to the extended-release formulation, individual variability must be considered. In patients who have VPA levels near the very high end of the therapeutic range (>100 microg/ml), it may be more prudent to make only minor modifications to the total daily dose during conversion and then to individualize the DVP extended-release dose based on plasma levels.
authors.affiliation: Virginia Commonwealth University, Division of Child Neurology, Children's Pavilion, Richmond, Virginia 23298-0211, USA. 9lkernit@mail2.vcu.edu
authors.forename: Lydia
authors.initials: L
authors.lastname: Kernitsky
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: O'Hara
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
authors.forename: John M
authors.initials: JM
authors.lastname: Pellock
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000553:Ambulatory Care; D002214:Capsules; D002648:Child; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D004334:Drug Administration Schedule; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D016896:Treatment Outcome; D014635:Valproic Acid / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*
chemical_list: D002214:Capsules; D003692:Delayed-Action Preparations; D014635:Valproic Acid