Hormone Agonists and Antagonists Flashcards
Technically, not all the drugs in this group are properly antagonists - some are agonists that compete with hormones for a receptor, while the true antagonists interact with the ligand to prevent receptor binding, and still others have both agonist and antagonist actions. To make the cards flow better, I refer to all drugs in this category simply as "hormone antagonists." Please don't hate me!
Hormone antagonists are currently used to treat what 3 types of cancers?
Lymphomas/leukemias, breast cancer, and prostate cancer
What group of hormone antagonist drugs is used to treat lymphomas and leukemias?
Glucocorticoids
List 3 different types of hormone antagonists that are used to treat breast cancer.
SERMs (Selective Estrogen-Receptor Modulators), SERDs (SER Downregulators), and aromatase inhibitors
Complete androgen ablation therapy requires 2 different kinds of hormone antagonists. What are these 2 categories?
GnRH analogs and nonsteroidal androgen-receptor blockers
Name the 2 glucocorticoid hormone antagonists.
Prednisone and dexamethasone
Which hormone antagonist is a SERM (selective estrogen-receptor modulator)?
Tamoxifen
Which hormone antagonist is a SERD (selective estrogen-receptor downregulator)?
Fulvestrant
What are the 4 aromatase inhibitors?
Aminoglutethamide, anastrozole, letrozole, and exemestane
What are the 2 GnRH analogs?
Leuprolide and goserelin
Name the 2 nonsteroidal androgen-receptor blockers.
Flutamide and bicalutamide
By what mechanism do the glucocorticoids inhibit cancer?
They inhibit lymphocyte mitosis
Which hormone antagonist is used to treat ALL, as well as Hodgkins, non-Hodgkins, multiple myeloma, and CLL.
Prednisone
How is dexamathasone typically used?
In conjunction with radiation therapy, to reduce edema in brain and spinal cord tumors
As a group, the hormone antagonists are notable for not inducing what common chemotherapy side-effect?
They do not cause myelosuppression
Which hormone antagonist, which can be administered orally, is the most widely used anti-estrogen therapy?
Tamoxifen
Tamoxifen therapy is unfortunately accompanied by hot flushes, alopecia, and increased risk of what 2 events?
Increased risks of endometrial cancer and of thromboembolism
How do tamoxifen and fulvestrant compare in terms of their mechanistic effect on ERs (estrogen/estradiol receptor)?
Fulvestrant binds ER with ~100x greater affinity than tamoxifen does, and reduces overall ER levels while tamoxifen stabilizes or even increases ER expression.
List 3 circumstances in which tamoxifen might be used.
For metastatic ER-positive breast cancer, as adjuvant therapy following breast tumor excision, or for prevention in high-risk (strong family history) patients
Even though we refer to the “hormone antagonists” as a class of cancer drugs, only 1 breast cancer drug is a true “anti-estrogen” antagonist that blocks estrogen from its receptor without displaying any agonist activity. Which drug is this?
Fulvestrant
Which aromatase inhibitor is a first-line therapy for treating ER(+) breast cancer in postmenopausal women?
Anastrozole
What is an obvious, must-not-miss feature that should be found for a cancer before it is treated with estrogen or androgen inhibiting drugs?
The cancer must be ER(+) or AR(+)
Which first generation estrogen inhibitor has fallen out of favor because it is relatively weak and has significant toxicity?
Aminoglutethamide
Which aromatase inhibitor is a steroidal inhibitor, meaning that it binds covalently and irreversibly?
Exemestane
Which estrogen inhibitors are used only on postmenopausal women?
Fulvestrant, anastrozole, letrozole, and exemestane
