This is a summary of the CPIC dosing guideline for tamoxifen and variation in the gene CYP2D6.
Patients with reduced cyp2d6 function may this can result in an increased risk of breast cancer recurrence. as a result, the guideline recommends an alternative an alternative hormonal therapy should also be considered for cyp2d6 intermediate metabolizers. a link to the original pathway is provided in the description below this video. it is metabolized by a number of
Enzymes, including cyp2d6. in cyp2d6 intermediate or poor metabolizers, formation of endoxifen is reduced. there are almost 150 different cyp2d6 alleles, each star allele can be assigned an activity this table gives the activity values of some cyp2d6 star alleles. links to these are given in the description below this video. gives further examples of alleles with their be
Aware that some cyp2d6 alleles have an should be interpreted with caution on a genetic test. in addition, an important caveat for all genotyping this can include rare increased-function, which are not routinely screened for in some genotyping tests. this reflects its significantly reduced function more information on the project can be found on the cpic website. is still
Given an activity value of 0.5 in the original manuscript. this update has not altered the guideline recommendations. reports in the scientific literature have alleles which are present in multiple copies of copies of that allele that are present in a genome. the activity score of alleles that are present the activity score for the allele by the number of copies present.
Further information about cyp2d6 alleles can be found at the pharmvar website at www.pharmvar.org. a link to pharmvar is also given in the description below this video. the cyp2d6 activity score is then used to note that genetic tests from different laboratories may not use this scheme to assign cyp2d6 metabolizer because of this, the guideline advises that activity
Score calculated before making clinical these are the cpic dosing recommendations for tamoxifen. these patients can begin tamoxifen therapy patients with a cyp2d6 normal metabolizer patients with a cyp2d6 intermediate metabolizer have reduced plasma concentrations of endoxifen an alternative hormonal therapy can be considered for these patients. 1 will have reduced plasma
Concentrations patients with a cyp2d6 poor metabolizer phenotype endoxifen and are at a higher risk of breast cancer recurrence. a dose increase can be considered for these detailed footnotes pertaining to the recommendations as a reminder, the recommendations presented this change in activity value does not alter the recommendations. this includes a drop-down menu where
An activity the activity summary includes implications appropriate dosing recommendation for the remember that variation in other genes in including concomitant medications, can affect treatment. cpic and pharmgkb assume no responsibility or property arising out of or related to any the guideline itself and supplementary information you can access relevant pages using the
Links in the description below this video.
Transcribed from video
CPIC guideline for tamoxifen and CYP2D6 By PharmGKB