Estrogen Receptor Antagonists

Question 1

What drugs are in the Estrogen Receptor Antagonists class?

Answer 1

Drugs in this class are:
- Tamoxifen
- Fulvestrant
- Elacestrant
- Toremifene

Question 2

What is the brand name of Tamoxifen?

Answer 2

The brand name of this generic drug is:
- Soltamox
- Nolvadex

Question 3

What is the brand name of Fulvestrant?

Answer 3

The brand name of this generic drug is:
- Faslodex

Question 4

What is the brand name of Elacestrant?

Answer 4

The brand name of this generic drug is:
- Orserdu

Question 5

What is the brand name of Toremifene?

Answer 5

The brand name of this generic drug is:
- Fareston

Question 6

What is the generic of name of Soltamox?

Answer 6

The generic name of this brand name drug is:
- Tamoxifen

Question 7

What is the generic of name of Nolvadex?

Answer 7

The generic name of this brand name drug is:
- Tamoxifen

Question 8

What is the generic of name of Faslodex?

Answer 8

The generic name of this brand name drug is:
- Fulvestrant

Question 9

What is the generic of name of Orserdu?

Answer 9

The generic name of this brand name drug is:
- Elacestrant

Question 10

What is the generic of name of Fareston?

Answer 10

The generic name of this brand name drug is:
- Toremifene

Question 11

What are the main/common indications of the Estrogen Receptor Antagonists class?

Answer 11

The main/common indications of this drug class are:
- Breast Cancer

Question 12

What is the class and MOA of Tamoxifen?

Answer 12

This drug in the following class:
- Estrogen Receptor Antagonists

This drug’s MOA is as follows:
- Binds to estrogen receptors on tumors and other tissue targets inhibiting estrogens effects and thus tumor growth

Question 13

What is the class and MOA of Fulvestrant?

Answer 13

This drug in the following class:
- Estrogen Receptor Antagonists

This drug’s MOA is as follows:
- Binds to estrogen receptors on tumors and other tissue targets inhibiting estrogens effects and thus tumor growth

Question 14

What is the class and MOA of Elacestrant?

Answer 14

This drug in the following class:
- Estrogen Receptor Antagonists
- Selective estrogen receptor degrader (SERD)

This drug’s MOA is as follows:
- Elacestrant is an estrogen receptor antagonist and nonsteroidal selective estrogen receptor degrader (SERD), which degrades estrogen receptor alpha in a dose-dependent manner, and inhibits estradiol-dependent estrogen-receptor directed gene transcription and tumor growth.

Question 15

What is the class and MOA of Toremifene?

Answer 15

This drug in the following class:
- Estrogen Receptor Antagonists

This drug’s MOA is as follows:
- Binds to estrogen receptors on tumors and other tissue targets inhibiting estrogens effects and thus tumor growth

Question 16

What are the notable/common monitoring parameters for the Estrogen Receptor Antagonists class?

Answer 16

The notable/common monitoring parameters for this drug class are:
- Bone mineral density at baseline and periodically during treatment (every 1-2 years)
- Gynecologic exam (baseline and annually, continuing after discontinuation of therapy)
- Liver function tests periodically during therapy

Question 17

Describe the emetic potential of the Estrogen Receptor Antagonists class.

Answer 17

The emetic potential of this drug class is:
- None, N/A

Question 18

Describe the extravasation risk and management strategies for the Estrogen Receptor Antagonists class.

Answer 18

The extravasation risk and management strategies for this drug class are as follows:
- None, N/A (all are oral)

Question 19

Describe the metabolism of the Estrogen Receptor Antagonists class.

Answer 19

The metabolism of this drug class is as follows:
- Primarily hepatic (mainly CYP2D6 for tamoxifen, mainly CYP3A4 for the others)

Question 20

What are the notable ADRs of Tamoxifen?

Answer 20

The notable ADRs of this drug are:
- Hot flashes
- Thromboembolism
- Endometrial malignancies

Question 21

What are the notable/common ADRs of the Estrogen Receptor Antagonists class?

Answer 21

The notable/common ADRs of this drug class are:
- See tamoxifen (possible class effect?)

Question 22

What drug(s) of the Estrogen Receptor Antagonists class is notable for causing hot flashes?

Answer 22

The drugs in this class notable for cause this condition are:
- Tamoxifen (possible class effect?)

Question 23

What drug(s) of the Estrogen Receptor Antagonists class is notable for causing thromboembolism?

Answer 23

The drugs in this class notable for cause this condition are:
- Tamoxifen (possible class effect?)

Question 24

What drug(s) of the Estrogen Receptor Antagonists class is notable for causing endometrial malignancies?

Answer 24

The drugs in this class notable for cause this condition are:
- Tamoxifen (possible class effect?)

Question 25

Describe the strategy and rationale for management of hot flashes caused by tamoxifen.

Answer 25

The strategy and rationale for management of this condition caused by this drug are:
- Chemotherapy + this drug can cause more frequent and severe hot flashes than natural menopause, which often results in decreased quality of life and may affect medication adherence.
- This is thought to be due to a central nervous system antiestrogenic effects causing thermoregulatory dysfunction.
- 80% of women prescribed this drug complain of hot flashes, with 30% of those having severe symptoms.
- Venlafaxine 75 mg orally daily has been shown to be more effective in managing hot flashes when compared to placebo, clonidine and gabapentin.
- Data also supports the use of paroxetine, fluoxetine, sertraline, and citalopram to manage hot flashes.
- *Drug interaction with CYP2D6

Question 26

Describe the strategy and rationale for management of thromboembolism caused by tamoxifen.

Answer 26

The strategy and rationale for management of this condition caused by this drug are:
- There is a significant procoagulant effect when this drug is added to chemotherapy.

Question 27

Describe the strategy and rationale for management of thromboembolism caused by endometrial malignancies.

Answer 27

The strategy and rationale for management of this condition caused by this drug are:
- Women taking tamoxifen should be informed about the risks of endometrial proliferation, endometrial hyperplasia, endometrial cancer, and uterine sarcomas.
- The risk of developing endometrial cancer from tamoxifen is about 1 in 500.
- Any abnormal vaginal bleeding, bloody vaginal discharge, or spotting should be investigated in post-menopausal women.
- Premenopausal women treated with tamoxifen have no known increased risk of uterine cancer and require no additional monitoring beyond routine gynecologic care.

Question 28

What are the risk factors for developing hot flashes with by tamoxifen?

Answer 28

Risk factors for developing this ADR with this drug/class are:
- Coadministration with chemotherapy?
- Premenopausal women
- Polymorphisms in drug metabolizing enzymes
- Coadministration of drugs that inhibit the activity of CYP2D6
- Specific estrogen receptor genotypes

Question 29

What are the risk factors for developing thromboembolism with by tamoxifen?

Answer 29

Risk factors for developing this ADR with this drug/class are:
- Coadministration with chemotherapy?
- The relative risks of venous thromboembolism are increased 2-3-fold in older women receiving tamoxifen and this elevated risk continues as long as the patient takes the drug.

Question 30

What are the clinical pearls of Tamoxifen?

Answer 30

The clinical pearls of this drug are as follows:
- Oral solution is bioequivalent to tamoxifen tablets
- It is the endocrine agent of choice for the adjuvant treatment of premenopausal women with breast cancer and for postmenopausal women who are not candidates for an aromatase inhibitor for whatever reason.
- Converted to its active metabolites by CYP2D6 and UGT2B7 - drugs that inhibit CYP2D6 (fluoxetine and paroxetine) may potentially alter the metabolism of tamoxifen.
- Unlike the aromatase inhibitors, this drug may help prevent bone loss and lowers total cholesterol

Question 31

What are the clinical pearls of the Estrogen Receptor Antagonists class?

Answer 31

The clinical pearls of this drug class are as follows:
- See tamoxifen (possible class effect?)