Definition: One of the SELECTIVE ESTROGEN RECEPTOR MODULATORS with tissue-specific activities. Tamoxifen acts as an anti-estrogen (inhibiting agent) in the mammary tissue, but as an estrogen (stimulating agent) in cholesterol metabolism, bone density, and cell proliferation in the ENDOMETRIUM.
4-hydroxytamoxifen [ 4'-hydroxytamoxifen,4-OHT hydrotamoxifen,4-hydroxy-tamoxifen,4-hydroxytamoxifen, (E)-isomer,4-hydroxytamoxifen, (Z)-isomer,4-monohydroxytamoxifen,ICI 79280,para-hydroxytamoxifen,tamoxifen metabolite B ] an antiestrogen; RN given refers to cpd without isomeric designation