Hormonal agents 1 Flashcards
Selective Estrogen-Receptor Modulators include
Tamoxifen and Raloxifene
SERM mechanisms of action
Tamoxifen acts as a competitive partial agonist of estrogen and binds to estrogen receptors
What are the toxicities of SERMs?
menopausal symptoms, thromboembolic events, mental “fogginess”
How do ramoxifene and tamoxifen differ?
Ramoxifene has anti-estrogen effects in the uterus. Tamoxifen has anti-estrogen effects in the breast tissue. Ramoxifene has less side effects and Tamoxifen has higher risk of endometrial hyperplasia
Selective estrogen receptor downregulators include
Fulvestrant
What is the MoA of fulvestrant?
anti-estrogen that binds to receptors. 100 times the affinity of tamoxifen. Binds sterically and leads to an increase in estrogen turnover, suppressing expression of estrogen-dependant genes
What are the side effects of fulvestrant?
well tolerated, but can have nausea, vasodilation, headache
What is the difference between SERMs and SERDs?
SERDs are devoid of agonist activity - only anti-estrogen “pure ER antagonists”, and have a better safety profile (think side effects), faster onset and longer duration of action. Tamoxifen does not reduce number of estrogen receptor molecules
Androgen Receptor antagonists/inhibitors include
Flutamide and Enzalutamide
Androgen receptor inhibitors MoA
bind to androgen receptor and competitively inhibit binding of testosterone, also inhibit AR translocation, DNA binding and activation
Androgen receptor antagonist side effects
mild nausea, hot flashes, gynecomastia, decreased libido. Enzalutamide specifically - increased risk of seizures, dizziness, muscular weakness
What are SERDs usually used for?
prostate cancers in combination with radiation
Enzalutamide is contraindicated in what population?
women who are pregnant or may become pregnant (birth defects)
