Background and objectives: 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.
Methods: 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.
Results: 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 ± 64.2 mg and 129.3 ± 44.6 mg, respectively (p = 0.043).
Conclusions: 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.