Endocrine Pharmacology Practice Questions

Q: Which of the following drugs is NOT used in the treatment of obesity?

Prednisone. ### Explanation The correct answer is **D. Prednisone**. **1. Why Prednisone is the correct answer:** Prednisone is a systemic corticosteroid used for its potent anti-inflammatory and immunosuppressive properties. Unlike the other options, it is **not** used to treat obesity; in fact, **weight gain** and central obesity (Cushingoid features) are classic side effects of chronic glucocorticoid therapy [3]. Prednisone promotes adipogenesis and increases appetite, making it contraindicated for weight loss [2]. **2. Analysis of incorrect options:** * **A. Orlistat:** A potent, reversible **gastric and pancreatic lipase inhibitor**. It prevents the hydrolysis of dietary fats (triglycerides) into absorbable free fatty acids, leading to decreased caloric absorption. It is FDA-approved for long-term obesity management. * **B. Sibutramine:** A **serotonin-norepinephrine reuptake inhibitor (SNRI)** that acts centrally to increase satiety [1]. Note: It has been withdrawn in many countries (including India and the USA) due to increased risks of cardiovascular events (MI and stroke), but it remains a classic textbook example of an anti-obesity drug. * **C. Rimonabant:** A selective **Cannabinoid-1 (CB1) receptor antagonist** [2]. It was designed to reduce appetite and cravings. However, it was withdrawn globally due to severe psychiatric side effects, including depression and suicidal ideation [2]. **3. High-Yield Clinical Pearls for NEET-PG:** * **Liraglutide & Semaglutide:** GLP-1 receptor agonists are currently the "gold standard" and high-yield for recent exams. * **Lorcaserin:** A 5-HT2C receptor agonist (withdrawn recently due to cancer risk). * **Phentermine/Topiramate:** A popular combination therapy for weight loss. * **Steatorrhea:** The most common side effect of Orlistat (due to fat malabsorption); managed by a low-fat diet and fat-soluble vitamin supplementation.

Q: Oral contraceptive pills can cause all of the following except:

Dysmenorrhea. **Explanation:** The correct answer is **Dysmenorrhea**. Oral Contraceptive Pills (OCPs) are actually a primary medical treatment for dysmenorrhea, rather than a cause of it. **Why Dysmenorrhea is the correct answer:** Combined OCPs work by inhibiting ovulation and suppressing endometrial proliferation. This leads to a thinner endometrial lining and a significant reduction in the synthesis of **Prostaglandins (PGF2α and PGE2)**. Since prostaglandins are the primary mediators of uterine contractions and pain during menstruation, OCPs effectively alleviate spasmodic dysmenorrhea. **Analysis of Incorrect Options:** * **Mastalgia (Breast tenderness):** This is a common side effect of the **estrogen** component in OCPs, which causes ductal proliferation and fluid retention in breast tissue. * **Chloasma (Melasma):** Also known as the "mask of pregnancy," this is a hyperpigmentation of the face caused by estrogen-induced stimulation of melanocytes. It is a well-documented dermatological side effect of OCPs. * **Breakthrough bleeding:** This refers to unscheduled spotting between periods. it is most common during the first few months of OCP use or with "low-dose" estrogen pills, occurring because the thin endometrium becomes fragile and sheds irregularly. **High-Yield NEET-PG Pearls:** 1. **Beneficial effects of OCPs:** Reduced risk of Ovarian cancer, Endometrial cancer, Benign breast disease, and Ectopic pregnancy. 2. **Absolute Contraindications:** History of Thromboembolism, Undiagnosed vaginal bleeding, Estrogen-dependent tumors (Breast CA), Smokers >35 years, and Active Liver disease. 3. **Drug Interaction:** Enzyme inducers like **Rifampicin** and **Phenytoin** decrease the efficacy of OCPs, leading to contraceptive failure.

Q: Tamoxifen is:

A non-steroidal antioestrogenic agent.. **Explanation:** **Tamoxifen** is a **Selective Estrogen Receptor Modulator (SERM)**. It is a **non-steroidal** compound that acts as a competitive antagonist at estrogen receptors in the breast tissue, making it a mainstay in the treatment of estrogen receptor-positive (ER+) breast cancer. **Why Option B is Correct:** Tamoxifen binds to estrogen receptors (ER), preventing estrogen from binding. In breast tissue, it acts as an **antioestrogen**, inhibiting the growth of estrogen-dependent cancer cells. Because its chemical structure is not based on the four-ring cholesterol backbone, it is classified as **non-steroidal**. **Why Other Options are Incorrect:** * **Option A:** Tamoxifen does not target progesterone receptors; drugs like **Mifepristone** are antiprogesterones. * **Option C:** **Norethindrone** is a 19-nortestosterone derivative used in oral contraceptives, not a SERM. * **Option D:** **Finasteride** and **Dutasteride** are the competitive inhibitors of 5-alpha-reductase, used in BPH and male pattern baldness. **High-Yield Clinical Pearls for NEET-PG:** * **Dual Action:** While Tamoxifen is an antagonist in the breast, it acts as a **partial agonist** in the **endometrium** and **bone**. * **Side Effects:** Its agonist action on the uterus increases the risk of **endometrial carcinoma**. It also increases the risk of **thromboembolism** (DVT/PE). * **Benefits:** It helps prevent osteoporosis by maintaining bone mineral density (agonist effect on bone). * **Drug of Choice:** It is the DOC for breast cancer in **pre-menopausal** women (Aromatase inhibitors are preferred in post-menopausal women).

Q: Bisphosphonates are prescribed to a patient with which of the following advice?

Take on an empty stomach with plenty of water.. **Explanation:** **1. Why Option A is Correct:** Bisphosphonates (e.g., Alendronate, Risedronate) have extremely **poor oral bioavailability** (typically <1%). Their absorption is significantly further impaired by the presence of food, calcium, iron, or beverages other than plain water. Therefore, they must be taken on an **empty stomach** (at least 30 minutes before the first food or drink of the day) with a **full glass of plain water** to ensure adequate systemic absorption. **2. Why Other Options are Incorrect:** * **Option B:** Taking the drug after meals would render it almost entirely unabsorbed due to chelation with dietary cations and interference from food particles. * **Option C:** While bisphosphonates can cause esophageal irritation, mild gastritis is often managed by ensuring the patient remains upright for 30 minutes. Discontinuation is usually reserved for severe esophageal ulceration or strictures, not every instance of gastric upset. * **Option D:** Severe bone, joint, or muscle pain is a known side effect of bisphosphonates. While it may require clinical review, it is not a standard "advice" given at the start of therapy compared to the critical administration instructions. **High-Yield NEET-PG Clinical Pearls:** * **The "Upright" Rule:** Patients must remain upright (sitting or standing) for at least 30 minutes after ingestion to prevent **pill-induced esophagitis** and esophageal reflux. * **Mechanism of Action:** They inhibit **osteoclast-mediated bone resorption** by inducing osteoclast apoptosis. * **Key Side Effects:** 1. **Erosive Esophagitis** (most common clinical concern). 2. **Osteonecrosis of the Jaw (ONJ)** (associated with high-dose IV use/dental procedures). 3. **Atypical Subtrochanteric Fractures** (with long-term use). * **Drug of Choice:** Bisphosphonates are the first-line treatment for **Postmenopausal Osteoporosis** and **Paget’s disease**.

Q: Which of the following is an indication for the use of raloxifene?

Post-menopausal osteoporosis. **Raloxifene** is a **Selective Estrogen Receptor Modulator (SERM)** [1, 2]. Its clinical utility stems from its unique tissue-specific action: it acts as an **estrogen agonist in bone** and an **estrogen antagonist in the breast and uterus** [1].1. **Why Option D is Correct:** In post-menopausal women, estrogen deficiency leads to increased osteoclast activity and bone loss. Raloxifene binds to estrogen receptors in the bone, inhibiting bone resorption and increasing bone mineral density [1, 2]. It is specifically FDA-approved for the **prevention and treatment of post-menopausal osteoporosis** [1]. A major advantage over HRT (Hormone Replacement Therapy) is that it reduces the risk of invasive breast cancer due to its antagonistic effect on breast tissue [1].2. **Why Other Options are Incorrect:** * **Chronic Renal Failure (A) & Renal Osteodystrophy (C):** These conditions involve complex disturbances of calcium, phosphate, and Vitamin D metabolism (secondary hyperparathyroidism). Management requires phosphate binders, Vitamin D analogues (Calcitriol), or Calcimimetics (Cinacalcet), not SERMs. * **Hypoparathyroidism (B):** This is characterized by low PTH levels leading to hypocalcemia. Treatment involves Calcium and Vitamin D supplements or recombinant PTH (Teriparatide/Natpara).**High-Yield Clinical Pearls for NEET-PG:** * **The "Good":** Decreases risk of vertebral fractures and reduces the risk of estrogen-receptor-positive breast cancer.* **The "Bad" (Side Effects):** Increases the risk of **Deep Vein Thrombosis (DVT)** and pulmonary embolism. It can also worsen **hot flashes** (unlike HRT, which treats them).* **The "Neutral":** Unlike Tamoxifen, Raloxifene is an **antagonist in the endometrium**, so it does *not* increase the risk of endometrial carcinoma.

Q: Which long-acting insulin can be mixed with rapid-acting insulin?

Degludec. **Explanation:** The correct answer is **Degludec**. **1. Why Degludec is correct:** Most long-acting insulin analogs are formulated at a specific pH that prevents them from being mixed with other insulins. However, **Insulin Degludec** is formulated at a neutral pH (7.4). It exists as soluble di-hexamers in the vial; upon subcutaneous injection, it forms multi-hexamer chains that slowly release monomers into the circulation. Because it is soluble at neutral pH, it can be co-formulated or mixed with rapid-acting insulins (like Insulin Aspart) without altering the pharmacokinetic profile of either component. This led to the development of **IDegAsp**, the first soluble combination of a basal and bolus insulin. **2. Why other options are incorrect:** * **Glargine (Option A):** It is formulated at an **acidic pH (4.0)**. If mixed with rapid-acting insulins (which are neutral), the glargine will precipitate prematurely in the syringe, making the onset and peak of both insulins unpredictable. * **Detemir (Option C):** While it has a neutral pH, its unique mechanism of action (binding to albumin via a fatty acid chain) can be interfered with if mixed, potentially altering its long-acting properties. Clinical guidelines generally advise against mixing it. * **Option D:** While true for Glargine, it is not a universal rule for all long-acting insulins, as Degludec is an exception. **High-Yield NEET-PG Pearls:** * **Ultra-long acting:** Degludec has a half-life of >25 hours and a duration of action >42 hours. * **Stability:** Degludec has the lowest risk of nocturnal hypoglycemia among basal insulins. * **Mixing Rule:** Regular insulin can be mixed with NPH (Intermediate), but always draw the **Clear (Regular) before the Cloudy (NPH)**.

Q: Which drug is used for the management of obesity?

Orlistat. **Explanation:** **Correct Option: A. Orlistat** Orlistat is a potent, specific, and long-acting **inhibitor of gastric and pancreatic lipases**. Its mechanism of action involves forming a covalent bond with the active serine site of these enzymes in the lumen of the stomach and small intestine. This prevents the hydrolysis of dietary fat (triglycerides) into absorbable free fatty acids and monoglycerides. Consequently, approximately 30% of dietary fat remains unabsorbed and is excreted in the feces, leading to a caloric deficit and weight loss. **Incorrect Options:** * **B. Rivastigmine:** A pseudo-irreversible acetylcholinesterase inhibitor used primarily in the management of **Alzheimer’s disease** and Parkinson’s dementia. * **C. Nitrous oxide:** An inhalational anesthetic gas (Laughing gas) used for **general anesthesia** and analgesia. * **D. Phenylephrine:** A selective **$\alpha_1$-adrenergic agonist** used as a nasal decongestant and a pressor agent to treat hypotension. **Clinical Pearls for NEET-PG:** * **Side Effects of Orlistat:** Due to fat malabsorption, it commonly causes **steatorrhea** (oily spotting), flatus with discharge, and fecal urgency. It can also interfere with the absorption of **fat-soluble vitamins (A, D, E, K)**; supplementation is often required. * **Other FDA-approved drugs for Obesity:** * **Liraglutide/Semaglutide:** GLP-1 receptor agonists (injectable). * **Phentermine/Topiramate:** Combination therapy (sympathomimetic + antiepileptic). * **Naltrexone/Bupropion:** Combination targeting reward pathways. * **Lorcaserin:** 5-HT$_{2C}$ agonist (withdrawn in many regions due to cancer risk).

Question 1

Which of the following drugs is NOT used in the treatment of obesity?

Accepted Answer

Prednisone

Answer

Orlistat

Answer

Sibutramine

Answer

Rimonabant

Question 2

A 47-year-old male presented with signs and symptoms of acromegaly. Radiologic studies showed the presence of a large pituitary tumor. Surgical treatment of the tumor was only partially effective in controlling the disease. At this point, which of the following drugs is most likely to be used as pharmacological therapy?

Accepted Answer

Octreotide

Answer

Desmopressin

Answer

Leuprolide

Answer

Somatropin

Question 3

A pregnant female with thyrotoxicosis is planned for surgery. Before surgery can be done, her gland should be reduced in size and vascularity by administering which of the following?

Accepted Answer

Propylthiouracil

Answer

Iodide ion

Answer

Propranolol

Answer

Radioactive iodine

Question 4

Oral contraceptive pills can cause all of the following except:

Accepted Answer

Dysmenorrhea

Answer

Mastalgia

Answer

Chloasma

Answer

Breakthrough bleeding

Question 5

Tamoxifen is:

Accepted Answer

A non-steroidal antioestrogenic agent.

Answer

A non-steroidal antiprogesterone.

Answer

Synthetic progestogen norethindrone.

Answer

A competitive inhibitor of 5-alpha-reductase.

Question 6

Bisphosphonates are prescribed to a patient with which of the following advice?

Accepted Answer

Take on an empty stomach with plenty of water.

Answer

Take after meals.

Answer

Discontinue if gastritis develops.

Answer

Discontinue if severe bone pain occurs.

Question 7

Which of the following is an indication for the use of raloxifene?

Accepted Answer

Post-menopausal osteoporosis

Answer

Chronic renal failure

Answer

Hypoparathyroidism

Answer

Renal osteodystrophy

Question 8

Which long-acting insulin can be mixed with rapid-acting insulin?

Accepted Answer

Degludec

Answer

Glargine

Answer

Detemir

Answer

Cannot be mixed due to difference in pH

Question 9

Which drug is used for the management of obesity?

Accepted Answer

Orlistat

Answer

Rivastigmine

Answer

Nitrous oxide

Answer

Phenylephrine

Question 10

Bisphosphonates are used in all of the following conditions EXCEPT:

Accepted Answer

Vitamin D excess

Answer

Paget's disease

Answer

Postmenopausal osteoporosis

Answer

Hypercalcemia of malignancy

Endocrine Pharmacology — MCQs

Endocrine Pharmacology — MCQs

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