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Population pharmacokinetics of valproate in Mexican children with epilepsy

Tania Correa1, Ildefonso Rodríguez, Silvia Romano

  • 1Pharmacy Department, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Manuel Nava No 6, San Luis Potosí, México.

Biopharmaceutics & Drug Disposition
|December 11, 2008
PubMed

Insights

Valproate clearance in Mexican pediatric epilepsy patients is influenced by total body weight, daily dose, and phenobarbital use. These factors are crucial for optimizing valproate dosage regimens.

Area of Science:

  • Pharmacokinetics
  • Pediatric Epilepsy

Background:

  • Valproic acid (VPA) is a common antiepileptic drug.
  • Understanding VPA clearance (CL) is vital for effective treatment in children.
  • Sparse VPA serum concentrations were analyzed from routine clinical care.

Purpose of the Study:

  • To identify factors affecting VPA CL in Mexican pediatric epilepsy patients.
  • To develop a population pharmacokinetic model for VPA.

Main Methods:

  • A mixed-effect model was employed using NONMEM software.
  • 110 pediatric patients with epilepsy were included.
  • Covariates tested included body weight, dose, age, sex, and comedications (phenobarbital, carbamazepine).

Main Results:

  • The final model: CL/F=(0.0466+0.00363 TBW+0.000282 DD)*(1+0.236 PB).
  • Total body weight (TBW), daily dose (DD), and phenobarbital (PB) significantly impacted VPA CL.
  • The model reduced interindividual variability by 50% and residual variability by 31%.

Conclusions:

  • TBW, DD, and PB are key determinants of VPA kinetic disposition in pediatric epilepsy.
  • These factors should guide VPA dosage regimen programming.
  • The model's validation supports its clinical applicability.
Abstract

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