Single-dose pharmacokinetics of lamotrigine in children: Influence of age and antiepileptic comedication

Dina Battino, Danilo Croci, Tiziana Granata, Daniela Mamoli, Sara Messina, Emilio Perucca

Research output: Contribution to journalArticle

Abstract

To evaluate the influence of pediatric age and antiepileptic comedication on the single-dose pharmacokinetics of lamotrigine, 19 patients with epilepsy (10 comedicated with enzyme inducers and 9 comedicated with valproic acid) aged 8 months to 30 years received a single oral dose of lamotrigine (0.6 to 2.2 mg/kg) after an overnight fast. Blood samples were collected for at least 36 hours and plasma lamotrigine concentrations were determined by high-performance liquid chromatography. Pharmacokinetic parameters were calculated by noncompartmental analysis. Lamotrigine half-life (T1/2) and oral clearance (Cl/F) values were significantly lower and significantly higher, respectively, in patients comedicated with enzyme inducers than in those receiving valproic acid (T1/2 = 8.1 vs. 41.7 hours respectively, P <0.001; Cl/F = 0.11 vs. 0.04 L/h per kg respectively, P <0.005, geometric means), whereas Cmax and Tmax values were comparable in the two groups. The differences in pharmacokinetic parameters persisted when comparisons were made within subgroups stratified according to age. Within groups of patients homogeneous for type of comedication, Cmax and AUC values tended to be lower in children aged less than 12 years than in older patients. There was no significant relationship between half-life values and age. The authors conclude that both age and type of comedication influence lamotrigine pharmacokinetics. The reduction in lamotrigine concentrations caused by enzyme inducers and the elevation caused by valproic acid can be explained by stimulation and inhibition, respectively, of lamotrigine glucuronidation. On the other hand, the lower plasma lamotrigine levels in children than in adolescents and older patients may not be explainable solely by differences in metabolic rate.

Original languageEnglish
Pages (from-to)217-222
Number of pages6
JournalTherapeutic Drug Monitoring
Volume23
Issue number3
DOIs
Publication statusPublished - Jun 2001

    Fingerprint

Keywords

  • Anticonvulsants
  • Children
  • Drug interaction
  • Lamotrigine
  • Pharmacokinetics

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Health, Toxicology and Mutagenesis
  • Pharmacology (medical)
  • Public Health, Environmental and Occupational Health
  • Pharmacology
  • Toxicology

Cite this