Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.

Valproic acid (VPA) is one of the most widely prescribed antiepileptic drugs for the treatment of epileptic seizures. Although it is well known that the doses of VPA and its plasma concentrations are highly correlated, the plasma concentrations do not correlate well with the therapeutic effects of t...

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Main Authors: Hiroo Nakashima, Kentaro Oniki, Miki Nishimura, Naoki Ogusu, Masatsugu Shimomasuda, Tatsumasa Ono, Kazuki Matsuda, Norio Yasui-Furukori, Kazuko Nakagawa, Takateru Ishitsu, Junji Saruwatari
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4617862?pdf=render
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author Hiroo Nakashima
Kentaro Oniki
Miki Nishimura
Naoki Ogusu
Masatsugu Shimomasuda
Tatsumasa Ono
Kazuki Matsuda
Norio Yasui-Furukori
Kazuko Nakagawa
Takateru Ishitsu
Junji Saruwatari
author_facet Hiroo Nakashima
Kentaro Oniki
Miki Nishimura
Naoki Ogusu
Masatsugu Shimomasuda
Tatsumasa Ono
Kazuki Matsuda
Norio Yasui-Furukori
Kazuko Nakagawa
Takateru Ishitsu
Junji Saruwatari
author_sort Hiroo Nakashima
collection DOAJ
description Valproic acid (VPA) is one of the most widely prescribed antiepileptic drugs for the treatment of epileptic seizures. Although it is well known that the doses of VPA and its plasma concentrations are highly correlated, the plasma concentrations do not correlate well with the therapeutic effects of the VPA. In this study, we developed a population-based pharmacokinetic (PK)-pharmacodynamic (PD) model to determine the optimal concentration of VPA according to the clinical characteristics of each patient. This retrospective study included 77 VPA-treated Japanese patients with epilepsy. A nonlinear mixed-effects model best represented the relationship between the trough concentrations of VPA at steady-state and an over 50% reduction in seizure frequency. The model was fitted using a logistic regression model, in which the logit function of the probability was a linear function of the predicted trough concentration of VPA. The model showed that the age, seizure locus, the sodium channel neuronal type I alpha subunit rs3812718 polymorphism and co-administration of carbamazepine, clonazepam, phenytoin or topiramate were associated with an over 50% reduction in the seizure frequency. We plotted the receiver operating characteristic (ROC) curve for the logit(Pr) value of the model and the presence or absence of a more than 50% reduction in seizure frequency, and the areas under the curves with the 95% confidence interval from the ROC curve were 0.823 with 0.793-0.853. A logit(Pr) value of 0.1 was considered the optimal cut-off point (sensitivity = 71.8% and specificity = 80.4%), and we calculated the optimal trough concentration of VPA for each patient. Such parameters may be useful to determine the recommended therapeutic concentration of VPA for each patient, and the procedure may contribute to the further development of personalized pharmacological therapy for epilepsy.
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spelling doaj.art-f533c6006052482a85e0a55b254d8a1f2022-12-21T19:46:30ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-011010e014126610.1371/journal.pone.0141266Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.Hiroo NakashimaKentaro OnikiMiki NishimuraNaoki OgusuMasatsugu ShimomasudaTatsumasa OnoKazuki MatsudaNorio Yasui-FurukoriKazuko NakagawaTakateru IshitsuJunji SaruwatariValproic acid (VPA) is one of the most widely prescribed antiepileptic drugs for the treatment of epileptic seizures. Although it is well known that the doses of VPA and its plasma concentrations are highly correlated, the plasma concentrations do not correlate well with the therapeutic effects of the VPA. In this study, we developed a population-based pharmacokinetic (PK)-pharmacodynamic (PD) model to determine the optimal concentration of VPA according to the clinical characteristics of each patient. This retrospective study included 77 VPA-treated Japanese patients with epilepsy. A nonlinear mixed-effects model best represented the relationship between the trough concentrations of VPA at steady-state and an over 50% reduction in seizure frequency. The model was fitted using a logistic regression model, in which the logit function of the probability was a linear function of the predicted trough concentration of VPA. The model showed that the age, seizure locus, the sodium channel neuronal type I alpha subunit rs3812718 polymorphism and co-administration of carbamazepine, clonazepam, phenytoin or topiramate were associated with an over 50% reduction in the seizure frequency. We plotted the receiver operating characteristic (ROC) curve for the logit(Pr) value of the model and the presence or absence of a more than 50% reduction in seizure frequency, and the areas under the curves with the 95% confidence interval from the ROC curve were 0.823 with 0.793-0.853. A logit(Pr) value of 0.1 was considered the optimal cut-off point (sensitivity = 71.8% and specificity = 80.4%), and we calculated the optimal trough concentration of VPA for each patient. Such parameters may be useful to determine the recommended therapeutic concentration of VPA for each patient, and the procedure may contribute to the further development of personalized pharmacological therapy for epilepsy.http://europepmc.org/articles/PMC4617862?pdf=render
spellingShingle Hiroo Nakashima
Kentaro Oniki
Miki Nishimura
Naoki Ogusu
Masatsugu Shimomasuda
Tatsumasa Ono
Kazuki Matsuda
Norio Yasui-Furukori
Kazuko Nakagawa
Takateru Ishitsu
Junji Saruwatari
Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.
PLoS ONE
title Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.
title_full Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.
title_fullStr Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.
title_full_unstemmed Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.
title_short Determination of the Optimal Concentration of Valproic Acid in Patients with Epilepsy: A Population Pharmacokinetic-Pharmacodynamic Analysis.
title_sort determination of the optimal concentration of valproic acid in patients with epilepsy a population pharmacokinetic pharmacodynamic analysis
url http://europepmc.org/articles/PMC4617862?pdf=render
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