Pharmacokinetics of topiramate during pregnancy

Epilepsy Res. 2009 Dec;87(2-3):124-9. doi: 10.1016/j.eplepsyres.2009.08.004. Epub 2009 Sep 8.

Abstract

Purpose: To study the effects of pregnancy on plasma concentrations of topiramate (TPM).

Methods: An established routine fluorescence polarization immunoassay (FPIA) method was used to determine TPM concentrations in 15 women with epilepsy treated with TPM during altogether 17 pregnancies.

Results: In 10 pregnancies, where samples were available from all three trimesters, the mean TPM dose/concentration ratio (D/C-ratio) was significantly higher than outside pregnancy baseline value 37.3 L/day (+/-15.9), during the 2nd, 67.5L/day (+/-23.4), and the 3rd trimester, 65.1L/day (+/-30.4), but not during the 1st, 49.4 L/day (+/-29.4). Including seven additional pregnancies enrolled late with data only from the 3rd trimester, the mean D/C-ratio during the 3rd trimester was 67.4 L/day (+/-27.5) compared to baseline, 38.8L/day (+/-18.0), an average increase by 71.8%. There was a pronounced intra-individual variability in alterations in D/C-ratios during pregnancies.

Conclusions: Our data show a significant pregnancy-related increase in D/C-ratios of TPM suggesting that therapeutic drug monitoring might be of value.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analysis of Variance
  • Anticonvulsants / pharmacokinetics
  • Dose-Response Relationship, Drug
  • Drug Monitoring
  • Epilepsy / drug therapy*
  • Female
  • Fluorescence Polarization Immunoassay
  • Fructose / analogs & derivatives*
  • Fructose / pharmacokinetics
  • Humans
  • Pregnancy
  • Pregnancy Trimester, Third
  • Topiramate

Substances

  • Anticonvulsants
  • Topiramate
  • Fructose