Tamoxifen pharmacokinetics and pharmacodynamics in older patients with non-metastatic breast cancer.
Esteban T D SouwerA Sanchez-SpitmanD J A R MoesH GelderblomJ J SwenJ E A PortieljeH J GuchelaarT van GelderPublished in: Breast cancer research and treatment (2023)
Serum concentrations of tamoxifen and its demethylated metabolites are higher in older patients, independent of CYP2D6 or CYP3A4 gene polymorphisms. A higher bioavailability of tamoxifen in older patients may explain the observed differences. However, clinical relevance of these findings is limited and should not lead to a different tamoxifen dose in older patients.