Differences in flurbiprofen pharmacokinetics between CYP2C9*1/*1, *1/*2, and *1/*3 genotypes

Area of Science:

• Pharmacogenomics
• Drug Metabolism
• Cytochrome P450 Enzymes

Background:

• Flurbiprofen is a nonsteroidal anti-inflammatory drug (NSAID) metabolized by the cytochrome P450 enzyme CYP2C9.
• Genetic variations in CYP2C9 can influence drug metabolism and patient response.
• Understanding genotype-specific metabolism is crucial for optimizing drug therapy.

Purpose of the Study:

• To investigate the impact of different CYP2C9 genotypes (*1/*1, *1/*2, *1/*3) on flurbiprofen metabolism.
• To quantify the relationship between CYP2C9 genotype and flurbiprofen pharmacokinetic parameters.

Main Methods:

• A single oral dose of flurbiprofen (50 mg) was administered to 15 individuals stratified by CYP2C9 genotype (*1/*1, *1/*2, *1/*3).
• Plasma and urine samples were collected over 24 hours post-dose.
• Pharmacokinetic analysis of flurbiprofen and its metabolite 4'-hydroxyflurbiprofen was performed.

Main Results:

• CYP2C9 genotype explained 59% of the variability in flurbiprofen exposure (AUC) and approximately 50% of the variability in clearance.
• Individuals with the CYP2C9*1/*3 genotype exhibited significantly higher flurbiprofen AUC and lower clearance compared to the *1/*1 genotype.
• No significant differences in flurbiprofen pharmacokinetics were observed between the *1/*2 and *1/*1 genotypes.

Conclusions:

• CYP2C9 genotype is a significant determinant of flurbiprofen pharmacokinetics in humans.
• The CYP2C9*3 allele markedly reduces flurbiprofen systemic clearance and increases exposure.
• These findings highlight the clinical relevance of CYP2C9 genotyping for personalized flurbiprofen dosing.