Endocrine Pharmacology Practice Questions

Q: GnRH agonist is used in all of the following EXCEPT?

Hypoestrogenism. The correct answer is **C. Hypoestrogenism**. **Mechanism of Action:** GnRH agonists (e.g., Leuprolide, Goserelin, Nafarelin) act on the pituitary gland. While an acute dose causes a "flare" of gonadotropins, **continuous/chronic administration** leads to the downregulation and desensitization of GnRH receptors [2]. This results in a state of **hypogonadotropic hypogonadism**, effectively lowering levels of estrogen and testosterone [2]. Therefore, GnRH agonists **cause** hypoestrogenism rather than treat it. **Analysis of Options:** * **A. Precocious Puberty:** Continuous GnRH agonists suppress the premature activation of the hypothalamic-pituitary-gonadal axis, delaying the onset of puberty and preventing premature epiphyseal closure [2]. * **B. Endometriosis:** These drugs create a "pseudomenopausal" state. By inducing hypoestrogenism, they cause the ectopic endometrial tissue to atrophy, providing symptomatic relief [1]. * **D. Congenital Adrenal Hyperplasia (CAH):** While not first-line, GnRH agonists are used as an adjunct in children with CAH who develop **secondary (central) precocious puberty** due to advanced bone age and early maturation of the axis. **Clinical Pearls for NEET-PG:** * **Pulsatile administration** of GnRH is used to treat **infertility** (stimulates FSH/LH) [2]. * **Continuous administration** is used for "medical castration" in **Prostate Cancer**, Endometriosis, and Uterine Fibroids [1]. * **Side Effects:** Hot flashes, decreased bone mineral density (osteoporosis), and vaginal dryness (all due to the induced hypoestrogenic state). * **Add-back therapy:** Low-dose estrogen/progestin is often given alongside GnRH agonists in endometriosis to prevent bone loss without losing the therapeutic effect.

Q: Galactorrhea may be associated with the use of all the following drugs except?

Pyridoxine. ### Explanation The physiological regulation of prolactin is primarily under the **inhibitory control of Dopamine** (Prolactin Inhibitory Factor) via D2 receptors in the anterior pituitary. Any drug that decreases dopamine levels or blocks its receptors will lead to hyperprolactinemia, resulting in **galactorrhea**. **Why Pyridoxine is the correct answer:** **Pyridoxine (Vitamin B6)** acts as a cofactor for the enzyme *L-amino acid decarboxylase*, which converts L-Dopa to Dopamine. By increasing peripheral dopamine synthesis, pyridoxine actually **suppresses prolactin secretion**. Historically, high doses of pyridoxine were used to treat lactation; therefore, it prevents rather than causes galactorrhea. **Analysis of Incorrect Options:** * **Methyldopa (Option A):** It is a centrally acting antihypertensive that acts as a "false neurotransmitter." It decreases central dopamine levels, leading to increased prolactin release. * **Tricyclic Antidepressants (Option B):** TCAs (like Amitriptyline) can cause galactorrhea by inhibiting dopamine activity or through mild serotonergic stimulation of prolactin. * **Phenothiazines (Option D):** These are typical antipsychotics (e.g., Chlorpromazine) that act as potent **D2 receptor antagonists** in the tuberoinfundibular pathway, making them a very common cause of drug-induced galactorrhea. **High-Yield Clinical Pearls for NEET-PG:** 1. **Metoclopramide and Domperidone** (anti-emetics) are frequent culprits of galactorrhea due to D2 blockade. 2. **Reserpine** causes galactorrhea by depleting dopamine stores. 3. **Bromocriptine and Cabergoline** (Dopamine agonists) are the drugs of choice for treating hyperprolactinemia/prolactinomas. 4. **Pyridoxine Interaction:** It reduces the efficacy of Levodopa in Parkinson’s disease by increasing its peripheral metabolism (unless a DOPA-decarboxylase inhibitor like Carbidopa is added).

Q: Bremelanotide is used for which of the following conditions?

Hypoactive sexual desire disorder. **Explanation:** **Bremelanotide** is a novel pharmacotherapy approved for the treatment of **Hypoactive Sexual Desire Disorder (HSDD)** in premenopausal women. **1. Why Option A is Correct:** Bremelanotide is a **melanocortin receptor agonist** (specifically targeting the MC4 receptor). Unlike Flibanserin (which acts on serotonin receptors), Bremelanotide works by modulating brain pathways involved in sexual desire and arousal. It is administered as a **subcutaneous injection** into the abdomen or thigh at least 45 minutes before anticipated sexual activity. It is indicated only for "acquired, generalized" HSDD, not for desire disorders caused by relationship issues or medical/psychiatric conditions. **2. Why Other Options are Incorrect:** * **Option B (LUTS):** Lower urinary tract symptoms are typically managed with alpha-blockers (e.g., Tamsulosin) or 5-alpha reductase inhibitors (e.g., Finasteride). * **Option C (Prostate Cancer):** Hormone refractory prostate cancer is treated with agents like Abiraterone, Enzalutamide, or Cabazitaxel. * **Option D (Renal Cell Carcinoma):** Metastatic RCC is managed with tyrosine kinase inhibitors (e.g., Sunitinib) or immunotherapy (e.g., Nivolumab). **High-Yield Clinical Pearls for NEET-PG:** * **FDA Approval:** Approved in 2019 (Brand name: Vyleesi). * **Mechanism:** MC4 receptor agonist. * **Route:** Subcutaneous (on-demand), unlike Flibanserin which is oral (daily). * **Side Effects:** The most common side effect is **nausea**. It can also cause a transient increase in blood pressure and focal hyperpigmentation (melasma). * **Contraindication:** Patients with uncontrolled hypertension or known cardiovascular disease.

Q: Ulipristal acetate is used for which of the following conditions?

Emergency contraception. **Explanation:** **Ulipristal acetate (UPA)** is a selective progesterone receptor modulator (SPRM). Its primary clinical application, and the correct answer here, is **Emergency Contraception (Option C)**. **Why Option C is correct:** Ulipristal acts by binding to progesterone receptors with high affinity, exerting an antagonistic effect. Its main mechanism is the **inhibition or delay of ovulation**. Unlike the levonorgestrel (LNG) pill, which must be taken within 72 hours and is ineffective once the LH surge has started, Ulipristal is effective for up to **120 hours (5 days)** after unprotected intercourse and can delay ovulation even after the LH surge has begun (but before it peaks). **Why other options are incorrect:** * **Option A (Endometriosis):** While some SPRMs are researched for endometriosis, Ulipristal is not the standard of care. GnRH analogues or progestins are preferred. * **Option B (Breast Cancer):** Antiestrogens (Tamoxifen) or Aromatase inhibitors are used here. Ulipristal is not indicated for breast malignancy. * **Option D (AUB):** While Ulipristal was previously used to treat **Uterine Fibroids** (to reduce volume and bleeding), its use for AUB/Fibroids has been severely restricted or suspended in many regions due to risks of **drug-induced liver injury**. **High-Yield Clinical Pearls for NEET-PG:** * **Dose:** 30 mg single dose for emergency contraception. * **Window:** Effective up to 120 hours (The "5-day pill"). * **Efficacy:** It is more effective than Levonorgestrel, especially in women with a higher BMI. * **Contraindication:** Severe asthma (due to its anti-glucocorticoid effect at high doses) and active liver disease. * **Note:** If a patient resumes regular hormonal contraception after taking UPA, they must use a barrier method for 14 days because UPA and progestins can interfere with each other.

Q: Which of the following statements is true about tamoxifen?

Selective estrogen receptor modulator. **Explanation:** **Tamoxifen** is the prototype **Selective Estrogen Receptor Modulator (SERM)** [2]. The core concept behind SERMs is their **tissue-specific action**: they act as competitive antagonists in some tissues while acting as partial agonists in others [2]. * **Why Option B is Correct:** Tamoxifen binds to estrogen receptors (ER), but its effect depends on the co-regulators present in the specific tissue [2]. It acts as an **antagonist in the breast** (inhibiting tumor growth) [1] but as an **agonist in the bone** (preventing bone loss) [3] and the **uterus** (stimulating endometrial proliferation) [2]. **Analysis of Incorrect Options:** * **Option A (SERD):** Selective Estrogen Receptor Downregulators (e.g., **Fulvestrant** [1]) bind to and trigger the degradation of the estrogen receptor. Unlike SERMs, they lack agonist activity [2]. * **Option C (STEAR):** Selective Tissue Estrogen Activity Regulators (e.g., **Tibolone**) are synthetic steroids used in HRT that have estrogenic, progestogenic, and androgenic properties. * **Option D (Estrogen Antagonist):** While Tamoxifen is an antagonist in the breast, calling it a pure antagonist is incorrect because it possesses significant agonist activity in other tissues [2]. **High-Yield Clinical Pearls for NEET-PG:** 1. **Clinical Use:** Drug of choice for ER-positive breast cancer in both pre- and post-menopausal women [1]. 2. **Side Effects:** Increased risk of **Endometrial Carcinoma** (due to uterine agonism) and **Thromboembolism** (DVT/PE) [1]. 3. **Beneficial Side Effect:** It decreases LDL levels and prevents postmenopausal osteoporosis [3]. 4. **Raloxifene:** Another SERM that is an antagonist in both breast and uterus, thus it does **not** increase the risk of endometrial cancer [3].

Q: Clomiphene citrate is not known to produce which of the following effects in a 30-year-old female?

Decreased FSH and LH secretion. **Explanation:** **Mechanism of Action and the Correct Answer:** Clomiphene Citrate (CC) is a Selective Estrogen Receptor Modulator (SERM). Its primary action is to act as a **competitive antagonist** at the estrogen receptors in the hypothalamus and pituitary gland. By blocking the negative feedback of endogenous estrogen, the body perceives a "hypoestrogenic" state. This triggers the pituitary gland to **increase** the secretion of **FSH and LH** (gonadotropins), which stimulates follicular development in the ovaries. Therefore, **Option C** is the correct answer because Clomiphene increases, rather than decreases, FSH and LH levels. **Analysis of Incorrect Options:** * **A. Hot flushes:** This is the most common side effect (approx. 10%). It occurs due to the anti-estrogenic effect of the drug on the thermoregulatory center in the hypothalamus. * **B. Ovulation:** This is the intended therapeutic effect. The rise in FSH leads to follicular growth, and the subsequent rise in estrogen eventually triggers an LH surge, leading to ovulation in 70-80% of patients. * **D. Polycystic ovaries:** Clomiphene causes ovarian stimulation. In some cases, this can lead to the formation of multiple follicular cysts or, in severe cases, Ovarian Hyperstimulation Syndrome (OHSS), making the ovaries appear polycystic or enlarged. **High-Yield NEET-PG Pearls:** * **First-line treatment:** Clomiphene is a traditional first-line drug for ovulation induction in PCOS (though Letrozole is now preferred in many guidelines due to higher live birth rates). * **Dose:** Usually started at 50 mg/day for 5 days, beginning on Day 2, 3, 4, or 5 of the menstrual cycle. * **Anti-estrogenic effects:** It can cause thinning of the endometrium and thickening of cervical mucus, which may lead to a "conception-ovulation gap" (high ovulation rate but lower pregnancy rate). * **Multiple Pregnancy:** There is an increased risk (approx. 5-10%), primarily twins.

Q: Which of the following statements about Afrezza is incorrect?

Substitute for long-acting insulin. ### Explanation **Afrezza** is a rapid-acting inhaled insulin formulation. Understanding its pharmacokinetics is crucial for identifying its clinical role. **1. Why Option B is the Correct (Incorrect Statement):** Afrezza is a **rapid-acting insulin** with an onset of action within 12–15 minutes and a short duration of approximately 180 minutes. Because it mimics the physiological "prandial" (mealtime) insulin spike, it **cannot substitute for long-acting (basal) insulin**. Patients with Type 1 Diabetes still require a long-acting injectable insulin (like Glargine or Degludec) to maintain basal glucose levels. **2. Analysis of Other Options:** * **Option A:** It is FDA-approved for both **Type 1 and Type 2 Diabetes Mellitus** to control mealtime glucose. * **Option C:** It is categorized as rapid-acting. Its peak action is reached faster than subcutaneous Lispro or Aspart. * **Option D:** It utilizes **Technosphere technology**, where insulin molecules are adsorbed onto fumaryl diketopiperazine (FDKP) microparticles. These particles are small enough to reach the alveoli for systemic absorption. **High-Yield Clinical Pearls for NEET-PG:** * **Contraindications:** Afrezza is strictly contraindicated in patients with chronic lung diseases like **Asthma or COPD** due to the risk of acute bronchospasm. * **Monitoring:** A baseline **Spirometry (FEV1)** is mandatory before initiation, at 6 months, and annually thereafter. * **Common Side Effect:** The most frequently reported adverse effect is a **dry cough**. * **Smokers:** It is not recommended in patients who smoke or have recently quit smoking (<6 months).

Q: Which of the following is NOT an adverse effect of estrogens?

Hot flushes. **Explanation:** The correct answer is **C. Hot flushes**. Estrogens are primarily used to **treat** vasomotor symptoms like hot flushes, not cause them. Hot flushes are a hallmark of estrogen deficiency (e.g., menopause) or the use of anti-estrogens (e.g., Tamoxifen, Clomiphene). Estrogens stabilize the thermoregulatory center in the hypothalamus; therefore, their administration relieves these symptoms. **Analysis of Incorrect Options:** * **A. Suppression of libido:** In males, exogenous estrogen inhibits the secretion of Gonadotropin-Releasing Hormone (GnRH) and Luteinizing Hormone (LH) via negative feedback. This leads to decreased endogenous testosterone production, resulting in decreased libido and erectile dysfunction. * **B. Fusion of epiphyses:** Estrogens play a critical role in bone maturation. High levels of estrogen (either endogenous during puberty or exogenous) promote the closure of epiphyseal plates in long bones, which halts linear growth. * **D. Gynecomastia in males:** Estrogens stimulate the proliferation of glandular breast tissue. In males, an increased estrogen-to-androgen ratio (due to exogenous intake or liver cirrhosis) leads to the development of breast tissue. **High-Yield Clinical Pearls for NEET-PG:** * **Vascular Risk:** Estrogens increase the risk of **Thromboembolism** (DVT/PE) by increasing the synthesis of clotting factors (II, VII, IX, X) and decreasing Antithrombin III. * **Carcinogenicity:** Unopposed estrogen therapy increases the risk of **Endometrial Carcinoma**; hence, Progestins are added in women with an intact uterus. * **Gallstones:** Estrogens increase cholesterol secretion in bile, leading to an increased risk of **cholelithiasis**. * **Migraine:** Estrogens can trigger or worsen migraine headaches due to vascular changes.

Q: Which type of cell does not increase by steroid administration?

Eosinophil. ### ExplanationGlucocorticoids (steroids) have a profound effect on the distribution and concentration of various blood cells. The key to answering this question lies in understanding the **"Steroid-induced Leukogram."****Why Eosinophils (and Monocytes/Lymphocytes) decrease:**Steroids cause a **decrease** in the circulating levels of **Eosinophils, Monocytes, and Lymphocytes**. They achieve this by:1. **Redistribution:** Shifting cells from the blood into other compartments (like the bone marrow or spleen).2. **Apoptosis:** Specifically inducing programmed cell death in eosinophils and certain T-lymphocytes.3. **Inhibition of recruitment:** Preventing their release into the peripheral circulation.**Analysis of Incorrect Options:*** **Neutrophils (D):** Steroids **increase** the neutrophil count. This occurs via "demargination"—neutrophils that were previously stuck to the blood vessel walls (marginal pool) are released into the circulating pool. Steroids also inhibit the migration of neutrophils out of the blood into tissues.* **RBCs (A):** Steroids **increase** Red Blood Cell production by stimulating erythropoiesis in the bone marrow [1]. This is why patients with Cushing’s syndrome often appear polycythemic.* **Platelets:** Though not an option here, it is high-yield to know that steroids also **increase** platelet counts [1].**NEET-PG High-Yield Pearls:*** **Mnemonic for Steroid Effects:** Steroids **"Drop"** the **B.E.L.M.** (Basophils, Eosinophils, Lymphocytes, Monocytes) and **"Raise"** the **R.P.N.** (RBCs, Platelets, Neutrophils).* **Clinical Significance:** A patient on high-dose steroids may show a high WBC count (leukocytosis) on a lab report. This is often due to neutrophil demargination and does not necessarily indicate a new infection.* **Lymphopenia:** Steroids are particularly toxic to T-cells, which is why they are used as immunosuppressants and in treating lymphomas.

Q: Treatment of diabetes insipidus includes all of the following EXCEPT:

Metformin. Diabetes Insipidus (DI) is characterized by a deficiency of Antidiuretic Hormone (ADH) or a resistance to its action, leading to polyuria and polydipsia [3]. **1. Why Metformin is the Correct Answer:** **Metformin** is a biguanide used primarily in the management of Type 2 Diabetes Mellitus. Its mechanism involves decreasing hepatic gluconeogenesis and improving insulin sensitivity. It has **no effect on ADH secretion or action** and does not possess any antidiuretic properties. Therefore, it plays no role in the treatment of DI. **2. Analysis of Incorrect Options:** * **Desmopressin (dDAVP):** This is a synthetic V2-selective analogue of ADH and is the **drug of choice** for Central DI [1, 2, 3]. It acts directly on the collecting ducts to increase water reabsorption [2]. * **Chlorpropamide:** A first-generation sulfonylurea that enhances the action of ADH on the renal tubules and may also stimulate ADH release from the posterior pituitary [1]. It is used as an adjuvant in partial central DI [1]. * **Carbamazepine:** Primarily an anticonvulsant, it is known to stimulate the release of ADH and is sometimes used in the management of partial central DI. **Clinical Pearls for NEET-PG:** * **Drug of Choice for Central DI:** Desmopressin (administered intranasally, orally, or parenterally) [1]. * **Drug of Choice for Nephrogenic DI:** Thiazide diuretics (e.g., Hydrochlorothiazide). They paradoxically reduce urine volume by inducing mild hypovolemia, which increases proximal tubule salt and water reabsorption. * **Lithium-induced Nephrogenic DI:** The specific treatment is **Amiloride**, which blocks the ENaC channels through which lithium enters the collecting duct cells. * **Chlorpropamide Side Effect:** It can cause a disulfiram-like reaction with alcohol and is a common cause of SIADH (hyponatremia) in the elderly.

Question 1

GnRH agonist is used in all of the following EXCEPT?

Accepted Answer

Hypoestrogenism

Answer

Delaying puberty in individuals with precocious puberty

Answer

Endometriosis

Answer

Congenital adrenal hyperplasia

Question 2

Galactorrhea may be associated with the use of all the following drugs except?

Accepted Answer

Pyridoxine

Answer

Methyldopa

Answer

Tricyclic antidepressants

Answer

Phenothiazine

Question 3

Bremelanotide is used for which of the following conditions?

Accepted Answer

Hypoactive sexual desire disorder

Answer

Lower urinary tract symptoms

Answer

Hormone refractory prostate cancer

Answer

Metastatic renal cell carcinoma

Question 4

Ulipristal acetate is used for which of the following conditions?

Accepted Answer

Emergency contraception

Answer

Endometriosis

Answer

Breast cancer

Answer

Abnormal uterine bleeding (AUB)

Question 5

Which of the following statements is true about tamoxifen?

Accepted Answer

Selective estrogen receptor modulator

Answer

Selective estrogen receptor downregulator

Answer

Selective tissue estrogen activator regulator

Answer

Estrogen antagonist

Question 6

Clomiphene citrate is not known to produce which of the following effects in a 30-year-old female?

Accepted Answer

Decreased FSH and LH secretion

Answer

Hot flushes

Answer

Ovulation

Answer

Polycystic ovaries

Question 7

Which of the following statements about Afrezza is incorrect?

Accepted Answer

Substitute for long-acting insulin

Answer

Used for both Type I and Type II diabetes

Answer

It is a rapid-acting insulin

Answer

Used as an inhaled insulin formulation with Technosphere technology

Question 8

Which of the following is NOT an adverse effect of estrogens?

Accepted Answer

Hot flushes

Answer

Suppression of libido

Answer

Fusion of epiphyses

Answer

Gynecomastia in males

Question 9

Which type of cell does not increase by steroid administration?

Accepted Answer

Eosinophil

Answer

RBC

Answer

Monocyte

Answer

Neutrophil

Question 10

Treatment of diabetes insipidus includes all of the following EXCEPT:

Accepted Answer

Metformin

Answer

Chlorpropamide

Answer

Desmopressin

Answer

Carbamazepine

Endocrine Pharmacology — MCQs

Endocrine Pharmacology — MCQs

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