title: Impact of the Cytochrome P450 2B6 (CYP2B6) Gene Polymorphism c.516G>T (rs3745274) on Propofol Dose Variability.
abstract: OBJECTIVE
  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.
authors.affiliation: Graduate Program in Biological Sciences and Rehabilitation, Methodist University Centre, IPA, Porto Alegre, RS, Brazil.
authors.forename: Artemísia L
authors.initials: AL
authors.lastname: Mourão
authors.affiliation: Graduate Program in Biological Sciences and Rehabilitation, Methodist University Centre, IPA, Porto Alegre, RS, Brazil.
authors.forename: Fabiana G
authors.initials: FG
authors.lastname: de Abreu
authors.affiliation: Graduate Program in Biological Sciences and Rehabilitation, Methodist University Centre, IPA, Porto Alegre, RS, Brazil. mariluf@ufcspa.edu.br.|Department of Basic Health Sciences, Federal Health Sciences University of Porto Alegre, Rua Sarmento Leite, 245/403, CEP 90050-170, Porto Alegre, RS, Brazil. mariluf@ufcspa.edu.br.
authors.forename: Marilu
authors.initials: M
authors.lastname: Fiegenbaum
mesh_terms: D000483:Alleles; D065702:Cytochrome P-450 CYP2B6 / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D015742:Propofol / Q000627:therapeutic use*
chemical_list: C585599:CYP2B6 protein, human; D065702:Cytochrome P-450 CYP2B6; D015742:Propofol