Impact of the Cytochrome P450 2B6 (CYP2B6) Gene Polymorphism c.516G>T (rs3745274) on Propofol Dose Variability.

Abstract

Propofol is the most commonly used hypnotic worldwide, but its effective dose varies greatly between individuals. The present study sought to investigate the relationship between the c.516G>T polymorphism in the CYP2B6 (cytochrome P450 2B6) gene and the required propofol dose. One hundred and eight patients treated with propofol were recruited, and environmental, clinical and surgical data were collected. Genotyping for the c.516G>T polymorphism was performed by real-time PCR. Multiple linear regression analysis was performed to estimate the predictive variables of the total propofol dose. For patients under general anaesthesia, the predictive variables of the total propofol dose were surgery duration (partial R (2)=19.9%), age (partial R (2)=10.5%), weight (partial R (2)=10.1%) and presence of the T allele (partial R (2)=6.8%). From the estimated coefficient of regression values, the surgery duration and weight were the factors that increased the propofol dose, while age and presence of the T allele decreased the total dose of the drug needed. The total propofol doses based on the GG or GT/TT genotypes were 151.5±64.2mg and 129.3±44.6mg, respectively (p=0.043). Our results indicate that 34% of the variance in the required propofol dose may be explained by these factors and that CYP2B6 c.516G>T polymorphism, which decreases the metabolism of the drug, accounts for approximately 7% of the drug dosage. Our results show the possible influence of CYP2B6 c.516G>T genetic variant on propofol dose in patients under general anaesthesia.