The effect of the cytochrome P450 CYP2C8 polymorphism on the disposition of (R)-ibuprofen enantiomer in healthy subjects.
OBJECTIVE
To study the effect of CYP2C8*3, the most common CYP2C8 variant allele on the dis-position of (R)-ibuprofen and the association of CYP2C8*3 with variant CYP2C9 alleles.


METHODS
Three hundred and fifty-five randomly selected Spanish Caucasians were screened for the common CYP2C8 and CYP2C9 mutations. The pharmacokinetics of (R)-ibuprofen were studied in 25 individuals grouped into different CYP2C8 genotypes.


RESULTS
The allele frequency of CYP2C8*3 (0.17) was found to be higher than that reported for other Caucasian populations (P = 0.0001). The frequencies of CYP2C9*2 and CYP2C9*3 were 0.19 (0.16-0.21) and 0.10 (0.08-0.12), respectively. An association between CYP2C8*3 and CYP2C9*2 alleles was observed, occurring together at a frequency 2.4-fold higher than expected for a random association of alleles (P = 0.0001). The presence of the CYP2C8*3 allele was found to influence the pharmacokinetics of (R)-ibuprofen in a gene-dose effect manner. Thus, after administration of 400 mg ibuprofen, the plasma half-life (95% confidence intervals) for individuals with genotypes CYP2C8*1/*1, CYP2C8*1/*3 and CYP2C8*3/*3, was 2.0 h (1.8-2.2), 4.2 h (1.9-6.5; P < 0.05) and 9.0 h (7.8-10.2; P < 0.002), respectively. A statistically significant trend with respect to the number of variant CYP2C8*3 alleles was also observed for the area under the concentration-time curve (P < 0.025), and drug clearance (P < 0.03).


CONCLUSIONS
Polymorphism of the CYP2C8 gene was found to be common, with nearly 30% of the population studied carrying the variant CYP2C8*3 allele. The presence of the latter caused a significant effect on the disposition of (R)-ibuprofen. This suggests that a substantial proportion of Caucasian subjects may show alterations in the disposition of drugs that are CYP2C8 substrates.
Martínez
Carmen
C
Department of Pharmacology, Medical School, University of Extremadura, Avda. De Elvas s/n, E-06071 Badajoz, Spain.
García-Martín
Elena
E
Blanco
Gerardo
G
Gamito
Francisco J G
FJ
Ladero
José M
JM
Agúndez
José A G
JA
D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D002851:Chromatography, High Pressure Liquid; D065727:Cytochrome P-450 CYP2C8; D065729:Cytochrome P-450 CYP2C9; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007052:Ibuprofen / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D013237:Stereoisomerism
C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases; C450259:CYP2C8 protein, human; D065727:Cytochrome P-450 CYP2C8; D007052:Ibuprofen