Hormonal Agents — MCQs
Which of the following is NOT effective in controlling the hot flushes of menopause in a woman?
Which drug is primarily used in the treatment of breast cancer?
A patient on tamoxifen therapy is most likely to develop which of the following?
What is the mechanism of action of fulvestrant?
Which of the following is not true regarding estrogen use in postmenopausal osteoporosis management?
HRT is helpful in all of the following except:
Which of the following is a testosterone inhibitor?
Which of the following statements about sitagliptin is false?
Secondary leukemias are caused by
Continuous GnRH therapy is used in All EXCEPT.
Hormonal Agents Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following is NOT effective in controlling the hot flushes of menopause in a woman?
- A. Raloxifene (Correct Answer)
- B. Isoflavones
- C. Hormone replacement therapy
- D. Tibolone
Explanation: ***Raloxifene*** - **Raloxifene** is a selective estrogen receptor modulator (SERM) that acts as an estrogen agonist in bone tissue, helping to prevent osteoporosis, but it is an estrogen antagonist in other tissues and can actually worsen or induce **hot flushes**. - Its primary indications are for the prevention and treatment of **osteoporosis** in postmenopausal women, and for the reduction of risk of invasive breast cancer in high-risk women. *Isoflavones* - **Isoflavones** (e.g., from soy) are phytoestrogens that can have weak estrogenic effects, and some women find them helpful in reducing the frequency and severity of **hot flushes**, though efficacy varies. - They bind to estrogen receptors, potentially mitigating the sudden drops in estrogen that lead to **vasomotor symptoms**. *Hormone replacement therapy* - **Hormone replacement therapy (HRT)**, which involves estrogen with or without progestin, is the most effective treatment for **menopausal hot flushes**. - By replacing declining estrogen levels, HRT directly addresses the underlying cause of **vasomotor instability**. *Tibolone* - **Tibolone** is a synthetic steroid that has estrogenic, progestogenic, and androgenic properties, and it is effective in relieving **menopausal hot flushes**. - It specifically targets estrogen receptors in the hypothalamus, which helps to stabilize **thermoregulatory control** and reduce hot flushes.
Question 2: Which drug is primarily used in the treatment of breast cancer?
- A. Tamoxifen (Correct Answer)
- B. Cyproterone
- C. Testosterone
- D. Chlorambucil
Explanation: ***Tamoxifen*** - **Tamoxifen** is a **selective estrogen receptor modulator (SERM)** primarily used to treat and prevent **estrogen receptor (ER)-positive breast cancer**. - It works by blocking estrogen from binding to receptors in breast cancer cells, thereby inhibiting their growth. *Cyproterone* - **Cyproterone** is an **anti-androgen** and **progestogen** primarily used to treat conditions like **prostate cancer**, **acne**, and **hirsutism** in women. - Its main mechanism involves blocking androgen receptors and reducing androgen production, which is not the primary pathway for breast cancer. *Testosterone* - **Testosterone** is an **androgen** (male sex hormone) and is **not used** in the primary treatment of breast cancer. - In certain rare cases of severe metastatic breast cancer, androgens like high-dose testosterone have been historically used for palliation, but this is not standard therapy. *Chlorambucil* - **Chlorambucil** is an **alkylating agent** used primarily in the treatment of **chronic lymphocytic leukemia (CLL)** and certain **lymphomas**. - It works by interfering with DNA replication and transcription, but it is not a first-line or primary agent for breast cancer.
Question 3: A patient on tamoxifen therapy is most likely to develop which of the following?
- A. Increased risk of breast cancer
- B. Increased LDL cholesterol levels
- C. Endometrial hyperplasia (Correct Answer)
- D. Increased risk of myocardial infarction
Explanation: ***Endometrial hyperplasia*** - Tamoxifen acts as an **estrogen receptor agonist** in the uterus, stimulating endometrial proliferation and increasing the risk of hyperplasia, polyps, and endometrial cancer. - This effect is particularly seen in **postmenopausal women** and is a major concern with long-term use. *Increased risk of breast cancer* - Tamoxifen is primarily used to **reduce the risk of breast cancer recurrence** and as a chemopreventive agent in high-risk individuals. - It acts as an **estrogen receptor antagonist** in breast tissue, blocking estrogen's proliferative effects. *Increased LDL cholesterol levels* - Tamoxifen typically has a favorable effect on lipids, often causing a **decrease in total and LDL cholesterol** levels. - This effect is due to its estrogenic activity in the liver. *Increased risk of myocardial infarction* - While tamoxifen can increase the risk of **thromboembolic events** (e.g., DVT, pulmonary embolism), it generally does not increase, and may even decrease, the risk of myocardial infarction due to its beneficial effects on lipid profiles. - Its overall cardiovascular risk profile is complex, but MI is not a commonly cited side effect.
Question 4: What is the mechanism of action of fulvestrant?
- A. Selective estrogen agonist
- B. Selective estrogen receptor modulator
- C. Selective estrogen receptor upregulator
- D. Selective estrogen receptor downregulator (Correct Answer)
Explanation: ***Selective estrogen receptor downregulator*** - Fulvestrant is classified as a **selective estrogen receptor downregulator (SERD)**. It binds to the estrogen receptor (ER) and promotes its degradation. - This effectively reduces the total number of ERs in the cell nucleus, leading to a profound anti-estrogenic effect without agonist activity. *Selective estrogen agonist* - An estrogen agonist would **activate estrogen receptors**, mimicking the effects of estrogen, which is not the therapeutic goal of fulvestrant in hormone-sensitive cancers. - Such a drug would promote tumor growth in estrogen-sensitive breast cancers. *Selective estrogen receptor modulator* - A selective estrogen receptor modulator (SERM) exhibits **tissue-specific agonist and antagonist effects** (e.g., tamoxifen acts as an antagonist in breast tissue but an agonist in bone). - Fulvestrant, in contrast, is a pure antagonist with no agonist activity and causes receptor degradation. *Selective estrogen receptor upregulator* - An upregulator would **increase the number of estrogen receptors**, potentially making cancer cells more sensitive to estrogen and promoting growth. - This mechanism is contrary to the therapeutic action of fulvestrant, which aims to reduce ER signaling.
Question 5: Which of the following is not true regarding estrogen use in postmenopausal osteoporosis management?
- A. Improves bone density
- B. Lowers breast cancer risk (Correct Answer)
- C. Increases thromboembolism risk
- D. May cause endometrial hyperplasia
Explanation: ***Lowers breast cancer risk*** - Estrogen use, particularly **combined estrogen-progestin therapy**, actually **increases** the risk of breast cancer, rather than lowering it [1]. - This increased risk is a significant concern and a primary reason why estrogen therapy is not a first-line treatment for osteoporosis [1]. *Improves bone density* - Estrogen therapy is known to **prevent bone loss** and **increase bone mineral density** in postmenopausal women by inhibiting osteoclast activity [1]. - This effect is beneficial in reducing the risk of osteoporotic fractures [1], [2]. *Increases thromboembolism risk* - Estrogen therapy significantly **increases the risk of venous thromboembolism (VTE)**, including deep vein thrombosis and pulmonary embolism. - This is a well-established adverse effect and a contraindication in women with a history of thrombotic events. *May cause endometrial hyperplasia* - Unopposed estrogen therapy can **stimulate endometrial proliferation**, leading to **endometrial hyperplasia** and an increased risk of endometrial cancer. - This is why progestin is typically added to estrogen therapy in women with an intact uterus.
Question 6: HRT is helpful in all of the following except:
- A. Vaginal atrophy
- B. Flushing
- C. Osteoporosis
- D. Coronary heart disease (Correct Answer)
Explanation: ***Coronary heart disease*** - Hormone Replacement Therapy (HRT) does not provide cardiovascular protection and may even increase the risk of **coronary heart disease (CHD)**, particularly in older women or those starting HRT many years after menopause. - The Women's Health Initiative (WHI) study demonstrated that HRT, specifically combined estrogen-progestin, increased the risk of **cardiovascular events** including myocardial infarction and stroke in postmenopausal women. - HRT is therefore **not recommended** for the prevention or treatment of coronary heart disease. *Vaginal atrophy* - HRT, particularly estrogen therapy (topical or systemic), is highly effective in treating **vaginal atrophy** by restoring vaginal tissue health. - Symptoms like **vaginal dryness**, itching, and dyspareunia are significantly improved with HRT. *Flushing* - HRT, especially estrogen, is very effective for reducing the frequency and severity of **hot flashes** and **flushing**, which are common vasomotor symptoms of menopause. - Estrogen stabilizes the thermoregulatory control center in the hypothalamus, alleviating these symptoms. *Osteoporosis* - HRT is approved for the prevention of **osteoporosis** in postmenopausal women because estrogen helps maintain bone mineral density and reduces the risk of fractures. - It helps to arrest bone loss and is a viable option for women at high risk who cannot take non-estrogen therapies.
Question 7: Which of the following is a testosterone inhibitor?
- A. Spironolactone (Correct Answer)
- B. Clomiphene
- C. Bremelanotide
- D. Sildenafil
Explanation: ***Spironolactone*** - Spironolactone is an **androgen receptor antagonist** and also inhibits **testosterone synthesis** by blocking 17α-hydroxylase and 17,20-lyase enzymes. - This dual action reduces the effects and production of testosterone, making it useful in conditions like **hirsutism** and **polycystic ovary syndrome (PCOS)**. *Clomiphene* - Clomiphene is a **selective estrogen receptor modulator (SERM)** that acts as an antagonist in the hypothalamus, thereby increasing the pulsatile release of GnRH. - This leads to increased FSH and LH secretion, stimulating **ovulation in women** and **testosterone production in men**, rather than inhibiting testosterone. *Bremelanotide* - Bremelanotide is a **melanocortin receptor agonist** that acts on the central nervous system to increase sexual desire. - It is used to treat **hypoactive sexual desire disorder (HSDD)** in premenopausal women and has no direct effect on testosterone levels or action. *Sildenafil* - Sildenafil is a **phosphodiesterase-5 (PDE5) inhibitor** that increases blood flow to the penis by enhancing the effects of nitric oxide, leading to an erection. - It is primarily used to treat **erectile dysfunction** and does not directly inhibit testosterone.
Question 8: Which of the following statements about sitagliptin is false?
- A. Used in type II diabetes mellitus
- B. Cannot be used orally (Correct Answer)
- C. Used in combination with other oral hypoglycemic agents
- D. All of the above statements are true
Explanation: ***Cannot be used orally*** - This statement is **false** because **sitagliptin** is an **oral medication** approved for the treatment of type 2 diabetes mellitus. - As a **DPP-4 inhibitor**, it is designed to be taken by mouth to increase incretin hormone levels. *Used in type II diabetes mellitus* - This statement is **true** as **sitagliptin** is a commonly prescribed **oral antidiabetic drug** for the management of type 2 diabetes. - It works by inhibiting the enzyme **dipeptidyl peptidase-4 (DPP-4)**, which increases levels of **GLP-1** and **GIP** to enhance insulin secretion and reduce glucagon secretion. *Used in combination with other oral hypoglycemic agents* - This statement is **true** as **sitagliptin** is often used as **add-on therapy** with other oral hypoglycemic agents like **metformin** or a **sulfonylurea** when monotherapy is insufficient. - This combination approach helps achieve better glycemic control by targeting different mechanisms of action. *All of the above statements are true* - This statement is **false** because the first statement "Cannot be used orally" is incorrect. - Since sitagliptin is indeed an oral medication, not all the above statements are true, making this option incorrect.
Question 9: Secondary leukemias are caused by
- A. Antimetabolites
- B. Vinca alkaloids
- C. Actinomycin D
- D. Alkylating agents (Correct Answer)
Explanation: ***Alkylating agents*** - **Alkylating agents**, such as **cyclophosphamide**, **chlorambucil**, **melphalan**, and **busulfan**, are highly associated with the development of secondary leukemias, particularly **acute myeloid leukemia (AML)** and **myelodysplastic syndrome (MDS)**. - They cause **DNA damage** by forming covalent bonds with DNA, leading to mutations and chromosomal aberrations (especially deletions of chromosomes 5 and 7) that can promote leukemogenesis. - The latency period is typically **5-7 years** after exposure, and the risk is dose-dependent. *Antimetabolites* - **Antimetabolites**, like **methotrexate** and **5-fluorouracil**, interfere with **DNA replication** and repair but are less frequently linked to secondary leukemias compared to alkylating agents. - While they can cause bone marrow suppression, their mechanism of action typically involves disrupting nucleotide synthesis rather than directly inducing the specific chromosomal changes seen in secondary leukemias. *Vinca alkaloids* - **Vinca alkaloids**, such as **vincristine** and **vinblastine**, primarily target **microtubule formation** and inhibit cell division, often used in cancer chemotherapy. - They are not a significant cause of secondary leukemias; instead, they primarily cause **neurotoxicity** and bone marrow suppression as side effects. *Actinomycin D* - **Actinomycin D** (dactinomycin) acts by intercalating into **DNA** and inhibiting RNA synthesis, making it an **antitumor antibiotic**. - While it is a potent chemotherapy agent with various side effects, it is not a primary cause of **secondary leukemias**, which are predominantly associated with alkylating agents and topoisomerase II inhibitors.
Question 10: Continuous GnRH therapy is used in All EXCEPT.
- A. Precocious puberty
- B. Prostate cancer
- C. Male infertility (Correct Answer)
- D. Endometriosis
Explanation: ***Male infertility*** - **Pulsatile GnRH therapy** is used to stimulate gonadotropin secretion and subsequent testosterone production in hypogonadotropic hypogonadism, which can cause male infertility. - **Continuous GnRH therapy** causes downregulation of GnRH receptors leading to suppression of gonadotropin release, which would worsen male infertility. *Precocious puberty* - Continuous GnRH therapy (GnRH agonists) is used to suppress the **pituitary-gonadal axis**, effectively stopping the progression of precocious puberty. - By continuously stimulating GnRH receptors, it leads to their **desensitization and downregulation**, preventing the pulsatile release of LH and FSH. *Prostate cancer* - Continuous GnRH therapy (GnRH agonists) is used for **androgen deprivation therapy**, suppressing testosterone production, which fuels prostate cancer growth. - This effectively creates a chemical castration effect by **downregulating GnRH receptors** on pituitary gonadotrophs. *Endometriosis* - Continuous GnRH therapy (GnRH agonists) is used to induce a **hypoestrogenic state**, which helps shrink endometrial implants. - By continuously stimulating GnRH receptors, it leads to their **desensitization and downregulation**, reducing estrogen production from the ovaries.
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