BACKGROUND Interindividual differences in CYP2D6 activity range from total absence of metabolism of certain drugs to ultrafast metabolism and can produce adverse effects or lack of therapeutic effect under standard therapy. Several mutations have been described in the CYP2D6 gene that abolish CYP2D6 activity. However, four mutations explain the majority of the poor metabolizers. We describe fou...

CYP2D6 is a highly polymorphic human gene responsible for a large variability in the disposition of more than 100 drugs to which humans may be exposed. Animal models are inadequate for preclinical pharmacological evaluation of CYP2D6 substrates because of marked species differences in CYP2D isoforms. To overcome this issue, a transgenic mouse line expressing the human CYP2D6 gene was generated....

In many black African populations, the capacity for CYP2D6-dependent drug metabolism is generally reduced. A specific variant of the CYP2D6 gene (CYP2D6*17) that carries three functional mutations (T107I, R296C, and S486T) has been found to be present in Zimbabwean subjects with impaired CYP2D6-dependent hydroxylase activity. To evaluate whether the CYP2D6*17 allele was the major cause behind t...

Objective(s): In this study, a cocktail of probe drugs was used to assess whether lentinan could influence the activities of rat enzymes CYP3A4, CYP2D6, CYP1A2, CYP2C19, and CYP2C9 in vivo. Materials and Methods: Fourteen days after intraperitoneal injection of lentinan, rats were given an oral dose of a cocktail solution containing phenacetin, tolbutamide, omeprazole, metoprolol, and midazolam...

BACKGROUND Controversy exists regarding the association between CYP2D6 enzyme activity and tamoxifen effectiveness in the adjuvant treatment of invasive breast cancer; however, this association in the primary prevention of breast cancer is unknown. METHODS We conducted a nested case-control study in the context of the NSABP P1 and P2 prevention trials to determine the impact of CYP2D6 genotyp...

Polymorphic expression of CYP2D6 contributes to the wide range of activity observed for this clinically important drug metabolizing enzyme. In this report we describe novel CYP2D7/2D6 hybrid genes encoding non-functional and functional CYP2D6 protein and a CYP2D7 variant that mimics a CYP2D7/2D6 hybrid gene. Five-kilobyte-long PCR products encompassing the novel genes were entirely sequenced. A...

Background: Controversy exists regarding the association between CYP2D6 enzyme activity and tamoxifen effectiveness in the adjuvant treatment of invasive breast cancer; however, this association in the primary prevention of breast cancer is unknown. Methods:We conducted a nested case–control study in the context of the NSABP P1 and P2 prevention trials to determine the impact of CYP2D6 genotype...

This study was conducted to investigate the effect of the reduced function allele CYP2D6*10, which can be the cause of an intermediate metabolizer (IM), on tolterodine pharmacokinetics. Tolterodine is mainly metabolized to an active 5-hydroxymethyl metabolite (5-HM) by CYP2D6, and 5-HM is also metabolized by CYP2D6. Asian and white healthy volunteers (n = 108) received once daily multiple doses...

Introduction Cytochrome P450 2D6 (CYP2D6) is a clinically important CYP, metabolising approximately 25% common drugs. We investigated the clinical effect of acute kidney injury (AKI) on hepatic CYP2D6 metabolism in critically ill adults, using the probe drug tramadol (abstract 470). We found no effect of AKI but a strong CYP2D6 genotype/phenotype influence on tramadol metabolism. Rodent studies...

Formalin-fixed, paraffin-embedded tumors (FFPETs) are a valuable source of DNA for genotype association studies and are often the only germline DNA resource from cancer clinical trials. The anti-estrogen tamoxifen is metabolized into endoxifen by CYP2D6, leading to the hypothesis that patients with certain CYP2D6 genotypes may not receive benefit because of their inability to activate the drug....