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Neurological Sciences
Published in: Neurological Sciences 3/2015

01-03-2015 | Original Article

The effect of polymorphic metabolism enzymes on serum phenytoin level

Authors: Aydan Ozkaynakci, Medine Idrizoglu Gulcebi, Deniz Ergeç, Korkut Ulucan, Mustafa Uzan, Cigdem Ozkara, Ilter Guney, Filiz Yilmaz Onat

Published in: Neurological Sciences | Issue 3/2015

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Abstract

Phenytoin has a widespread use in epilepsy treatment and is mainly metabolized by hepatic cytochrome P450 enzymes (CYP). We have investigated CYP2C9*2, CYP2C9*3, CYP2C19*2 and CYP2C19*3 allelic variants in a Turkish population of patients on phenytoin therapy. Patients on phenytoin therapy (n = 102) for the prevention of epileptic seizures were included. Polymorphic alleles were analyzed by restriction fragment length polymorphism method. Serum concentrations of phenytoin were measured by fluorescence polarization immune assay method. The most frequent genotype was detected for CYP2C9 wild-type alleles (78.43 %), whereas CYP2C19*2/*2 (5.88 %) was the least frequent genotype group. According to the classification made with both enzyme polymorphisms, CYP2C9*1/*1-CYP2C19*1/*1 (G1: 41.17 %) genotype group was the most frequent whereas CYP2C9*1/*2-CYP2C19*1/*3 (G7: 0.98 %) was the least frequent one. The highest mean phenytoin level (27.95 ± 1.85 µg/ml) was detected in the G8 genotype group (CYP2C9*1/*3-CYP2C19*2/*3) and the G1 genotype group showed the lowest mean phenytoin level (7.43 ± 0.73 µg/ml). The mean serum concentration of phenytoin of the polymorphic patients with epilepsy was higher than that for the wild-type alleles both in the monotherapy and polytherapy patients. These results show the importance of the genetic polymorphism analysis of the main metabolizing enzyme groups of phenytoin for the dose adjustment.
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Metadata
Title
The effect of polymorphic metabolism enzymes on serum phenytoin level
Authors
Aydan Ozkaynakci
Medine Idrizoglu Gulcebi
Deniz Ergeç
Korkut Ulucan
Mustafa Uzan
Cigdem Ozkara
Ilter Guney
Filiz Yilmaz Onat
Publication date
01-03-2015
Publisher
Springer Milan
Published in
Neurological Sciences / Issue 3/2015
Print ISSN: 1590-1874
Electronic ISSN: 1590-3478
DOI
https://doi.org/10.1007/s10072-014-1961-8

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