N-desmethyltamoxifen

N-desmethyltamoxifen is a primary metabolite of tamoxifen, a medication used in the treatment of breast cancer. It is produced in the body through the process of metabolism by the enzyme cytochrome P450.

Chemistry

N-desmethyltamoxifen is a nonsteroidal compound with a structure similar to that of estrogen. It is classified as a selective estrogen receptor modulator (SERM), meaning it has the ability to bind to estrogen receptors and either block or activate them, depending on the tissue type.

Pharmacology

In the body, tamoxifen is converted into N-desmethyltamoxifen by the enzyme cytochrome P450. This metabolite is then further metabolized into endoxifen, which is the most active form of the drug. The conversion of N-desmethyltamoxifen to endoxifen is primarily carried out by the enzyme CYP2D6.

Clinical significance

The levels of N-desmethyltamoxifen and endoxifen in the body can be influenced by a number of factors, including genetic variations in the CYP2D6 enzyme. Some individuals have a version of this enzyme that is less active, which can lead to lower levels of endoxifen and potentially reduce the effectiveness of tamoxifen treatment. This has led to research into the use of N-desmethyltamoxifen as a potential alternative to tamoxifen in individuals with reduced CYP2D6 activity.

See also

• Tamoxifen
• Endoxifen
• Cytochrome P450
• Selective estrogen receptor modulator