Endocrine Pharmacology — MCQs

A 29-year-old male patient presents to the OPD with a 10-year history of coarse facial features and progressive enlargement of the hands and feet. Laboratory evaluation revealed elevated IGF-1 and non-suppressible growth hormone levels after the 75 g glucose challenge test. A diagnosis of acromegaly is made. Which of the following drugs is preferred for the management of this patient?

Q646

A 28-year-old woman is prescribed an oral contraceptive pill. The packaging shown in the image contains pills organized by weeks with different colored pills for Week 1, Week 2, and Week 3. What type of combined oral contraceptive preparation is this?

Q647

A 60-year-old post-menopausal woman presents with low back ache and pain in all legs muscles. Her lab reports show normal serum calcium, phosphate and normal serum alkaline phosphatase. For management of this condition, which of the following drugs is given by intranasal route?

Q648

Select the correct composition of the OCP shown below:

Q649

Which of the following are major complications of oral pills? 1. Cholestasis jaundice 2. Chloasma and acne 3. Venous thromboembolism 4. Breast cancer Select the correct answer using the code given below.

Q650

All of the following are correct regarding drospirenone EXCEPT:

Endocrine Pharmacology Indian Medical PG Practice Questions and MCQs

Question 641: What is the drug of choice for a pregnant female suspected of having a baby with congenital adrenal hyperplasia?

A. Dexamethasone (Correct Answer)
B. Betamethasone
C. Hydrocortisone
D. Prednisolone

Explanation: ### Explanation **1. Why Dexamethasone is the Correct Choice:** The primary goal in treating a fetus suspected of having **Congenital Adrenal Hyperplasia (CAH)**—specifically 21-hydroxylase deficiency—is to prevent the **virilization of a female fetus**. To achieve this, the drug must cross the placenta in an active form to suppress the fetal pituitary-adrenal axis, thereby reducing the production of adrenal androgens. **Dexamethasone** is the drug of choice because it is **not inactivated by the placental enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2)**. This allows the drug to reach the fetal circulation in high concentrations to suppress fetal ACTH. Treatment must be started early (before the 9th week of gestation) to be effective. **2. Why the Other Options are Incorrect:** * **Betamethasone:** While it also crosses the placenta (used for fetal lung maturity), Dexamethasone is the established gold standard in clinical protocols for CAH prenatal prevention. * **Hydrocortisone and Prednisolone:** These are **extensively inactivated** by the placental enzyme 11β-HSD2 into inactive metabolites (e.g., Prednisolone is converted to Prednisone). Consequently, they do not reach the fetus in sufficient concentrations to suppress the fetal adrenal gland. These drugs are used to treat the *mother* if she has Addison’s disease, but not the *fetus*. **3. High-Yield Clinical Pearls for NEET-PG:** * **Placental Barrier:** Remember that 11β-HSD2 acts as a "gatekeeper." Fluorinated steroids like **Dexamethasone and Betamethasone** escape this degradation. * **Timing:** Treatment is started "blindly" as soon as pregnancy is confirmed and stopped if the fetus is later determined to be male or an unaffected female via CVS or amniocentesis. * **Side Effects:** Long-term maternal use of Dexamethasone can lead to Cushingoid features, gestational diabetes, and hypertension. * **Drug of Choice for Maternal Addison's in Pregnancy:** Hydrocortisone (because it *doesn't* cross the placenta, sparing the fetus from unnecessary steroid exposure).

Question 642: A drug used in the management of osteoporosis has the mechanism of action depicted in the accompanying figure. What is the likely identity of this drug?

A. Teriparatide
B. Alendronate
C. Denosumab (Correct Answer)
D. Estrogen

Explanation: ***Denosumab*** - **Monoclonal antibody** that specifically blocks **RANKL** (Receptor Activator of Nuclear factor Kappa-B Ligand) from binding to **RANK** receptors on osteoclast precursors. - This mechanism prevents **osteoclast formation and activation**, directly reducing bone resorption and increasing bone mineral density. *Teriparatide* - **PTH analog** with an **anabolic mechanism** that stimulates **osteoblast activity** and bone formation, rather than inhibiting RANKL. - Acts as a **bone-building agent** through intermittent dosing, promoting new bone matrix synthesis. *Alendronate* - **Bisphosphonate** that works by inhibiting **farnesyl pyrophosphate synthase** within osteoclasts, leading to osteoclast apoptosis. - Does not target the **RANKL-RANK pathway** but instead disrupts osteoclast metabolism through interference with the **mevalonate pathway**. *Estrogen* - Works through **multiple mechanisms** including upregulation of **OPG** (osteoprotegerin) and decreased **RANKL expression**, but is not a direct RANKL inhibitor. - Also has **receptor-mediated effects** on both osteoblasts and osteoclasts, making it less specific than targeted RANKL blockade.

Question 643: What percentage of Lente insulin is amorphous?

A. 70%
B. 30% (Correct Answer)
C. 50%
D. 90%

Explanation: **Explanation:** Lente insulin is an intermediate-acting insulin preparation categorized as a **Lente series** insulin. These are produced by complexing insulin with zinc in a buffered medium, without the addition of foreign proteins like protamine. The correct answer is **30%** because Lente insulin is a physical mixture of two components in a specific **7:3 ratio**: 1. **Ultralente (70%):** This is the **crystalline** form. It is poorly soluble and has a slow onset but a long duration of action. 2. **Semilente (30%):** This is the **amorphous** (non-crystalline) form. It is more soluble, providing a relatively quicker onset of action. **Analysis of Options:** * **Option B (30%) is Correct:** This represents the amorphous (Semilente) component of the mixture. * **Option A (70%):** This is incorrect because 70% represents the **crystalline** (Ultralente) portion of Lente insulin. * **Options C & D (50% and 90%):** These do not correspond to the standardized pharmaceutical formulation of Lente insulin. **High-Yield Clinical Pearls for NEET-PG:** * **Composition:** Lente = 70% Crystalline (Ultralente) + 30% Amorphous (Semilente). * **Mechanism:** The "Lente" effect is achieved by varying the zinc concentration and pH to alter solubility, not by adding protamine (unlike NPH insulin). * **Clinical Note:** Lente insulins are rarely used today due to the advent of recombinant DNA technology and long-acting analogs like Glargine and Detemir, which provide more predictable "peakless" profiles. * **NPH vs. Lente:** NPH (Neutral Protamine Hagedorn) uses protamine as a retarding agent, whereas Lente uses zinc.

Question 644: Which of the following does not cause insulin release?

A. Rosiglitazone (Correct Answer)
B. Nateglinide
C. Glimipiride
D. Tobutamide

Explanation: ### Explanation The key to answering this question lies in distinguishing between **Insulin Secretagogues** (drugs that stimulate insulin release) and **Insulin Sensitizers** (drugs that improve the body's response to existing insulin). #### 1. Why Rosiglitazone is the Correct Answer **Rosiglitazone** belongs to the **Thiazolidinedione (TZD)** class. Its primary mechanism of action is as a selective agonist for the nuclear receptor **PPAR-γ** (Peroxisome Proliferator-Activated Receptor gamma). It works by increasing the transcription of genes involved in glucose metabolism, thereby **increasing insulin sensitivity** in peripheral tissues (adipose, muscle, and liver). It does **not** act on the pancreatic beta cells to stimulate insulin secretion; hence, it does not cause hypoglycemia when used as monotherapy. #### 2. Why the Other Options are Incorrect * **Glimepiride and Tolbutamide:** These are **Sulfonylureas** (2nd and 1st generation, respectively). They stimulate insulin release by binding to the **SUR1 subunit** of the ATP-sensitive K⁺ channels in pancreatic beta cells, causing channel closure, depolarization, and subsequent calcium influx. * **Nateglinide:** This is a **Meglitinide/Phenylalanine derivative**. Like sulfonylureas, it acts as an insulin secretagogue by closing ATP-sensitive K⁺ channels, though it has a faster onset and shorter duration of action (primarily targeting postprandial glucose). #### 3. NEET-PG High-Yield Pearls * **Insulin Secretagogues:** Sulfonylureas and Meglitinides. These carry a high risk of **hypoglycemia** and **weight gain**. * **Insulin Sensitizers:** Biguanides (Metformin) and TZDs (Rosiglitazone, Pioglitazone). * **TZD Side Effects:** Weight gain (due to fluid retention and adipogenesis), edema, and increased risk of bone fractures. * **Contraindication:** Rosiglitazone is generally avoided in patients with **NYHA Class III/IV Heart Failure** due to fluid overload risks.

Question 645: A 29-year-old male patient presents to the OPD with a 10-year history of coarse facial features and progressive enlargement of the hands and feet. Laboratory evaluation revealed elevated IGF-1 and non-suppressible growth hormone levels after the 75 g glucose challenge test. A diagnosis of acromegaly is made. Which of the following drugs is preferred for the management of this patient?

A. Leuprolide
B. Ketoconazole
C. Lanreotide depot formulation (Correct Answer)
D. Terlipressin

Explanation: ***Lanreotide depot formulation***- This is a long-acting **somatostatin analog (SSA)** that binds to somatostatin receptors on the pituitary adenoma, effectively inhibiting the secretion of **growth hormone (GH)**.- SSAs, including lanreotide and **octreotide**, are considered the first-line medical therapy for acromegaly, especially when surgery fails or is contraindicated, as they control both GH and **IGF-1** levels.*Terlipressin*- *Terlipressin* is primarily used for the treatment of **bleeding esophageal varices** in patients with portal hypertension, as it acts as a **vasopressin analog** causing splanchnic vasoconstriction.- It has no therapeutic role in controlling sustained GH hypersecretion or managing the pituitary tumor responsible for **acromegaly**.*Ketoconazole*- *Ketoconazole* is primarily an **antifungal agent** but is occasionally used to inhibit **steroid biosynthesis** in conditions like **Cushing's syndrome** due to its effect on P450 enzymes.- It does not affect the production or secretion of **growth hormone** from the somatotropes and is therefore ineffective in treating **acromegaly**.*Leuprolide*- *Leuprolide* is a **Gonadotropin-Releasing Hormone (GnRH) agonist** used for conditions responsive to chemical castration, such as **prostate cancer** or **endometriosis**.- This agent targets the hypothalamic-pituitary-gonadal axis, having no clinical utility in directly suppressing the hypersecretion of **GH** in **acromegaly**.

Question 646: A 28-year-old woman is prescribed an oral contraceptive pill. The packaging shown in the image contains pills organized by weeks with different colored pills for Week 1, Week 2, and Week 3. What type of combined oral contraceptive preparation is this?

A. Monophasic combined OCP
B. Emergency pill
C. Biphasic combined OCP
D. Triphasic combined OCP (Correct Answer)

Explanation: ***Triphasic combined OCP*** - The image displays three distinct rows of pills for "Week 1", "Week 2", and "Week 3", and the text "all colored pills taking any white pills" implying a change in dosage or composition over the cycle. - **Triphasic pills** are designed to deliver varying levels of hormones (estrogen and progestin) in three sequential phases within the cycle to mimic the natural hormonal fluctuations. *Monophasic combined OCP* - **Monophasic pills** contain a constant dose of both estrogen and progestin throughout the active pill cycle. - The image clearly indicates different "weeks" and implies variation, which is characteristic of multiphasic, not monophasic, pills. *Emergency pill* - An **emergency contraceptive pill** is typically a single dose or two doses taken within a short timeframe after unprotected intercourse, not a 21-day pack with weekly indications. - Its purpose is to prevent pregnancy after sex, not for regular daily contraception over a menstrual cycle. *Biphasic combined OCP* - **Biphasic pills** have two different combinations of hormones per cycle, changing once during the 21-day active pill period. - The visual distinction of "Week 1", "Week 2", and "Week 3" strongly suggests three varying phases, making it triphasic rather than biphasic.

Question 647: A 60-year-old post-menopausal woman presents with low back ache and pain in all legs muscles. Her lab reports show normal serum calcium, phosphate and normal serum alkaline phosphatase. For management of this condition, which of the following drugs is given by intranasal route?

A. Teriparatide
B. Calcitonin (Correct Answer)
C. Cinacalcet
D. Zoledronate

Explanation: ***Calcitonin*** - Calcitonin is a hormone that inhibits **osteoclastic bone resorption** and can be administered via an **intranasal spray** for the management of osteoporosis. - While not a first-line treatment for osteoporosis, it's used in patients who cannot tolerate other therapies or for short-term pain relief in acute vertebral fractures. *Teriparatide* - **Teriparatide** is a recombinant form of **parathyroid hormone** that promotes **bone formation**. - It is administered via **subcutaneous injection**, not intranasally. *Zoledronate* - **Zoledronate** is a **bisphosphonate** that inhibits osteoclast activity and reduces bone turnover. - It is typically administered as an **intravenous infusion**, not intranasally. *Cinacalcet* - **Cinacalcet** is a **calcimimetic** drug that increases the sensitivity of calcium-sensing receptors on the parathyroid gland, thereby decreasing parathyroid hormone (PTH) secretion. - It is used to treat **secondary hyperparathyroidism** and **parathyroid carcinoma**, not directly for osteoporosis, and is administered **orally**.

Question 648: Select the correct composition of the OCP shown below:

A. Levonorgestrel 0.15 mg + Ethinyl estradiol 0.30 mg
B. Lynestrenol 0.15 mg + Ethinyl estradiol 0.03 mg
C. Levonorgestrel 0.15 mg + Ethinyl estradiol 0.03 mg (Correct Answer)
D. Lynestrenol 0.15 mg + Ethinyl estradiol 0.30 mg

Explanation: ***Levonorgestrel 0.15 mg + Ethinyl estradiol 0.03 mg*** - Mala-D is a common **combined oral contraceptive pill (COCP)** used in India, known for its specific formulation. - Its active ingredients are typically **Levonorgestrel 0.15 mg** (a progestin) and **Ethinyl estradiol 0.03 mg** (an estrogen). *Levonorgestrel 0.15 mg + Ethinyl estradiol 0.30 mg* - While containing Levonorgestrel, the **Ethinyl estradiol dosage of 0.30 mg is significantly higher** than typically found in standard Mala-D pills. - Such a high dose of estrogen would correspond to an older generation of OCPs or an uncommon formulation, not characteristic of Mala-D. *Lynestrenol 0.15 mg + Ethinyl estradiol 0.03 mg* - This option incorrectly identifies the progestin as **Lynestrenol**; Mala-D utilizes **Levonorgestrel** as its progestin component. - Although the Ethinyl estradiol dose is correct, the incorrect progestin makes this option unsuitable. *Lynestrenol 0.15 mg + Ethinyl estradiol 0.30 mg* - This combination is incorrect on two counts: it lists **Lynestrenol instead of Levonorgestrel** and has an **untypically high dose of Ethinyl estradiol (0.30 mg)** for a common OCP like Mala-D. - Standard Mala-D does not contain Lynestrenol, nor does it have such a high estrogen dosage.

Question 649: Which of the following are major complications of oral pills? 1. Cholestasis jaundice 2. Chloasma and acne 3. Venous thromboembolism 4. Breast cancer Select the correct answer using the code given below.

A. 1, 2 and 3 (Correct Answer)
B. 1, 3 and 4
C. 1, 2 and 4
D. 2, 3 and 4

Explanation: ***1, 2 and 3*** - **Cholestasis jaundice** is a rare but serious hepatic complication of oral contraceptive pills (OCPs), caused by the estrogen component leading to impaired bile flow. - **Venous thromboembolism (VTE)** is one of the most serious and well-documented major complications of OCPs, with increased risk particularly in the first year of use and with higher estrogen doses. - **Chloasma and acne** are common dermatological side effects of OCPs. While technically not "life-threatening major complications," they are clinically significant adverse effects that affect quality of life and compliance. Some classifications include these as "major" due to their frequency and impact on continuation. - Note: The distinction between "major complications" and "common side effects" can vary by source. This answer reflects the inclusive interpretation. *1, 3 and 4* - This option includes **breast cancer** as a major complication. Current evidence shows a small increased risk during active use that diminishes after discontinuation. However, the relationship is complex and not consistently classified as a "major complication" in standard teaching. - It excludes **chloasma and acne**, which are very common adverse effects frequently listed among OCP-related problems. *1, 2 and 4* - This option includes **breast cancer**, which has nuanced and often conflicting evidence regarding its association with OCPs. - It excludes **venous thromboembolism**, which is indisputably the most serious life-threatening complication of oral contraceptive use and must be included in any list of major complications. *2, 3 and 4* - This option excludes **cholestasis jaundice**, which is a recognized serious hepatic complication of OCPs. - It incorrectly includes **breast cancer** as a major complication while omitting cholestatic jaundice, which is more consistently classified as a complication in pharmacology texts.

Question 650: All of the following are correct regarding drospirenone EXCEPT:

A. It is safe in renal failure patients. (Correct Answer)
B. It has antimineralocorticoid action.
C. It is a fourth generation progestin.
D. It has antiandrogenic property.

Explanation: ***4. It is safe in renal failure patients*** - **Drospirenone** has **antimineralocorticoid activity**, which can lead to **hyperkalemia**, especially in patients with **renal impairment**. - Therefore, it is **contraindicated** and not safe in patients with **renal failure** due to the increased risk of potentially life-threatening **hyperkalemia**. *3. It has antimineralocorticoid action* - Drospirenone is a unique progestin derived from **spironolactone**, giving it a distinct **antimineralocorticoid effect**. - This effect helps to reduce symptoms like **bloating** and **fluid retention**, which are often associated with other hormonal contraceptives. *2. It has antiandrogenic property* - Drospirenone possesses significant **antiandrogenic properties**, which are beneficial in treating conditions like **acne** and **hirsutism**. - This action helps to counteract the androgenic side effects some other progestins might exhibit, making it a favorable choice for women who experience these issues. *1. It is a fourth generation progestin* - Drospirenone is classified as a **fourth-generation progestin**, developed to offer an improved side effect profile compared to older progestins. - These newer progestins often have more selective receptor binding and distinct pharmacological properties like **antiandrogenic** and **antimineralocorticoid** effects.

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