for the treatment of breast cancer
Nolvadex Mechanism Of Action:
Nolvadex binds to estrogen receptors (ER), inducing a conformational change in the receptor. This results in a blockage or change in the expression of estrogen dependent genes. The prolonged binding of tamoxifen to the nuclear chromatin of these results in reduced DNA polymerase activity, impaired thymidine utilization, blockade of estradiol uptake, and decreased estrogen response. It is likely that tamoxifen interacts with other coactivators or corepressors in the tissue and binds with different estrogen receptors, ER-alpha or ER-beta, producing both estrogenic and antiestrogenic effects.
Hepatic. Tamoxifen is extensively metabolized after oral administration. N-desmethyl tamoxifen is the major metabolite found in plasma. N-desmethyl tamoxifen activity is similar to tamoxifen. 4-Hydroxytamoxifen and a side chain primary alcohol derivative of tamoxifen have been identified as minor metabolites in plasma. Tamoxifen is a substrate of cytochrome P450 CYP3A4, CYP2C9 and CYP2D6, and an inhibitor of P-glycoprotein.