Endocrine Pharmacology Practice Questions

Q: Which of the following drugs does NOT produce gynecomastia?

Coisol. **Explanation:** Gynecomastia (enlargement of glandular breast tissue in males) occurs due to an imbalance between estrogenic and androgenic effects on breast tissue [1]. This can be caused by increased estrogen levels, decreased testosterone production, or displacement of testosterone from its receptors. **Why Coisol is the correct answer:** **Coisol** is a brand name for **Clotrimazole**, an imidazole antifungal. While systemic ketoconazole is a well-known cause of gynecomastia (due to inhibition of cytochrome P450 enzymes involved in testosterone synthesis) [1], topical or systemic Clotrimazole does not typically interfere with the steroidogenesis pathway to a degree that causes gynecomastia. **Analysis of incorrect options:** * **Cimetidine (Option A):** An H2-receptor antagonist that causes gynecomastia by two mechanisms: it has anti-androgenic effects (blocks androgen receptors) and inhibits the metabolism of estradiol, leading to increased estrogen levels. * **Digoxin (Option B):** It has a steroid-like structure similar to estrogen. Chronic use can lead to increased estrogenic activity and decreased LH/testosterone levels. * **Spironolactone (Option C):** A potassium-sparing diuretic that is a frequent cause of gynecomastia. It acts as an androgen receptor antagonist and also inhibits testosterone synthesis [1], [2]. **High-Yield Clinical Pearls for NEET-PG:** To remember the common drugs causing gynecomastia, use the mnemonic **"DISCO"**: * **D** – Digoxin * **I** – Isoniazid * **S** – Spironolactone * **C** – Cimetidine / Cyproterone / Cannabis * **O** – Oestrogens **Other notable causes:** Ketoconazole, Finasteride [1], and Methyldopa. Among these, **Spironolactone** is the most common culprit in clinical practice.

Q: Which of the following drugs does NOT cause gynecomastia?

Amiloride. **Explanation:** Gynecomastia (enlargement of male breast tissue) is a high-yield side effect in pharmacology, typically caused by drugs that increase estrogen levels, decrease testosterone synthesis, or block androgen receptors. **Why Amiloride is the correct answer:** **Amiloride** is a potassium-sparing diuretic that acts by blocking epithelial sodium channels (ENaC) in the distal tubule. Unlike **Spironolactone** (another potassium-sparing diuretic), Amiloride does not have any significant affinity for steroid receptors. Therefore, it does **not** cause endocrine side effects like gynecomastia or impotence. **Analysis of Incorrect Options:** * **Digoxin:** It has a steroid-like structure similar to estrogen. Chronic use can lead to increased estrogenic activity and decreased luteinizing hormone (LH), resulting in gynecomastia. * **Cimetidine:** This H2-receptor blocker has anti-androgenic effects. It inhibits the binding of dihydrotestosterone (DHT) to androgen receptors and inhibits the metabolism of estradiol. * **Ketoconazole:** This antifungal inhibits the enzyme **17,20-lyase** and **CYP11A1** (cholesterol side-chain cleavage enzyme), which are essential for testosterone synthesis, leading to an imbalance in the estrogen/androgen ratio. **NEET-PG High-Yield Pearls:** To remember the common causes of gynecomastia, use the mnemonic **"DISCO"**: * **D** – Digoxin * **I** – Isoniazid * **S** – Spironolactone (The most common diuretic cause) * **C** – Cimetidine * **O** – Oestrogens (or Ketoconazole) *Note:* If a patient develops gynecomastia while on Spironolactone, switching them to **Eplerenone** or **Amiloride** is the clinically preferred step.

Q: Which of the following drugs inhibits spermatogenesis?

Gossypol. **Explanation:** **Gossypol (Option B)** is the correct answer. It is a polyphenolic compound derived from the seeds of the cotton plant (*Gossypium* species). In males, Gossypol acts as a non-hormonal male contraceptive by inhibiting spermatogenesis. It works by suppressing the function of the germinal epithelium and inhibiting lactate dehydrogenase-X (LDH-X), an enzyme essential for the energy metabolism of sperm and spermatogenic cells. While effective, its clinical use is limited due to a high incidence of **hypokalemia** (leading to muscle weakness) and the risk of **permanent infertility** (irreversible azoospermia) in about 10–20% of users. **Analysis of Incorrect Options:** * **Gelusil (Option A):** An antacid containing Aluminum hydroxide and Magnesium hydroxide. It is used to neutralize gastric acid in dyspepsia and GERD. * **Gestodene (Option C):** A potent third-generation progestin used in combined oral contraceptive pills (COCPs) for females. It does not inhibit spermatogenesis in males. * **Gemcadiol (Option D):** A lipid-lowering agent (hypolipidemic drug) that structurally resembles fatty acids; it has no role in reproductive pharmacology. **High-Yield Clinical Pearls for NEET-PG:** * **Gossypol’s Side Effects:** The "Two H's" — **H**ypokalemia and **H**yper-irreversibility (permanent sterility). * **Other drugs causing male infertility:** Sulfasalazine (decreases sperm count/motility), Nitrofurantoin, Cyclophosphamide (alkylating agents), and Spironolactone (anti-androgenic effect). * **LDH-X:** This is the specific target of Gossypol found only in mature testes and sperm.

Q: Desmopressin can be used for all of the following conditions EXCEPT?

Nephrogenic diabetes insipidus. **Explanation:** Desmopressin (DDAVP) is a synthetic analog of Vasopressin (ADH) with high selectivity for **V2 receptors** and minimal V1 (vasoconstrictor) activity. **Why Nephrogenic Diabetes Insipidus (DI) is the correct answer:** In Nephrogenic DI, the kidneys are **unresponsive** to ADH due to genetic defects in V2 receptors or drugs like Lithium. Since the pathology lies in the end-organ resistance, administering exogenous ADH analogs like Desmopressin will not produce a therapeutic effect. The treatment of choice here is Thiazide diuretics or Amiloride. **Analysis of other options:** * **Neurogenic (Central) DI:** This is caused by a deficiency of ADH from the posterior pituitary. Desmopressin is the **drug of choice** as it replaces the missing hormone. * **Nocturnal Enuresis:** Desmopressin reduces urine production at night by increasing water reabsorption in the collecting ducts, making it a standard treatment for bed-wetting in children. * **Mild Hemophilia A & von Willebrand Disease (Type 1):** Desmopressin triggers the release of **Factor VIII and von Willebrand Factor (vWF)** from endothelial storage sites (Weibel-Palade bodies), helping in hemostasis. **High-Yield Clinical Pearls for NEET-PG:** * **Route:** Desmopressin is preferred over Vasopressin because it has a longer duration of action and can be given intranasally or orally. * **V1 vs. V2:** V1 receptors mediate vasoconstriction (used in esophageal varices); V2 receptors mediate water reabsorption and factor release. * **Side Effect:** The most serious side effect of Desmopressin is **hyponatremia**, which can lead to seizures. * **SIADH:** Desmopressin is contraindicated in SIADH as it would worsen water intoxication.

Q: Which of the following is NOT an adverse drug reaction of metformin?

Weight gain. Metformin, a **Biguanide**, is the first-line oral hypoglycemic agent for Type 2 Diabetes Mellitus. Understanding its side effect profile is crucial for NEET-PG. ### **Explanation of the Correct Answer** **B. Weight gain:** This is the correct answer because Metformin is **weight neutral** or often leads to **weight loss**. Unlike Sulfonylureas, Thiazolidinediones (TZDs), and Insulin—which are notorious for causing weight gain—Metformin improves insulin sensitivity and reduces appetite, making it the preferred drug for obese diabetic patients. ### **Analysis of Incorrect Options** * **A & C. Diarrhea and Nausea:** Gastrointestinal (GI) upset is the **most common** adverse effect of Metformin. Patients frequently report abdominal bloating, nausea, and osmotic diarrhea. These are usually dose-dependent and can be minimized by starting with a low dose or using extended-release formulations. * **D. Lactic Acidosis:** This is the **most serious/fatal** (though rare) complication. Metformin inhibits gluconeogenesis from lactate; in conditions of renal impairment, hypoxia, or severe infection, lactate accumulates, leading to metabolic acidosis. ### **High-Yield Clinical Pearls for NEET-PG** * **Mechanism of Action:** Activates **AMP-activated protein kinase (AMPK)**, leading to decreased hepatic glucose production (gluconeogenesis). * **Vitamin Deficiency:** Long-term use of Metformin is associated with **Vitamin B12 deficiency** due to interference with its absorption in the terminal ileum. * **Contraindication:** It is contraindicated if the **eGFR is <30 mL/min/1.73 m²** due to the high risk of lactic acidosis. * **Eugenlycemic:** Metformin does not cause hypoglycemia when used as monotherapy (it is an "euglycemic" agent).

Q: Which of the following drugs is administered in a pulsatile manner?

Goserelin. **Explanation:** The correct answer is **Goserelin (Option C)**. **Mechanism & Rationale:** Goserelin is a **GnRH (Gonadotropin-Releasing Hormone) agonist**. The physiological secretion of GnRH from the hypothalamus is naturally **pulsatile**, which stimulates the pituitary to release LH and FSH. * **Pulsatile administration** of GnRH agonists (like Goserelin or Leuprolide) mimics this natural rhythm and is used to **treat infertility** by inducing ovulation. * **Continuous (non-pulsatile) administration**, conversely, causes "downregulation" or desensitization of GnRH receptors, leading to medical castration. This is used for prostate cancer, endometriosis, and precocious puberty. **Analysis of Incorrect Options:** * **A. Octreotide:** A long-acting synthetic analogue of Somatostatin. It is administered via subcutaneous or IV routes (continuous or bolus) to inhibit growth hormone and GI hormones; it does not require pulsatile delivery. * **B. Abarelix:** A **GnRH antagonist**. Unlike agonists, antagonists block receptors immediately without an initial flare and do not require pulsatile administration to achieve their effect. * **D. Aspirin:** An NSAID and antiplatelet agent. It is administered in standard oral doses (daily or as needed) and has no relation to the pulsatile hormonal axis. **High-Yield Clinical Pearls for NEET-PG:** * **The "Flare" Phenomenon:** Continuous GnRH agonist therapy initially causes a transient rise in testosterone/estrogen (flare) before suppression. This is why GnRH antagonists (e.g., Degarelix) are preferred when immediate suppression is needed. * **Diagnostic Use:** Pulsatile GnRH can be used to differentiate between hypothalamic (Kallmann syndrome) and pituitary causes of hypogonadism. * **Key GnRH Agonists:** Remember the mnemonic **"Go Lean"** — **Go**serelin, **Leu**prolide, **Na**farelin.

Q: Which one of the following is a non-steroidal contraceptive?

Centchroman. **Explanation:** **Centchroman (Ormeloxifene)** is the correct answer because it is a **Selective Estrogen Receptor Modulator (SERM)** and is chemically a **non-steroidal** compound. Developed by CDRI, Lucknow (marketed as *Saheli* or *Chhaya*), it works by preventing the blastocyst from implanting in the uterine lining. It does not suppress ovulation but alters the cervical mucus and the endometrial receptivity (asynchrony between the embryo and the endometrium). **Analysis of Incorrect Options:** * **Mifepristone (RU-486):** This is a **synthetic steroid** with potent anti-progestational activity. While used for emergency contraception and medical abortion, it is structurally a steroid. * **Progestin-only pill (Minipill):** These contain low doses of **progestogens** (e.g., Levonorgestrel), which are synthetic derivatives of the steroid hormone progesterone. * **Norethisterone enanthate (NET-EN):** This is an injectable **progestin** (a 19-nortestosterone derivative), which is inherently a steroid molecule. **High-Yield Clinical Pearls for NEET-PG:** * **Dosage Schedule:** Centchroman is unique for its "Once-a-week" schedule (30 mg twice a week for the first 3 months, then once a week). * **Government Initiative:** It is included in the National Family Planning Programme of India under the brand name **'Chhaya'**. * **Side Effects:** The most common side effect is a **delay in the menstrual cycle** (prolonged cycles), but it does not cause the typical steroidal side effects like weight gain, nausea, or mood swings. * **Safety:** It is safe for use in breastfeeding mothers as it does not affect the quantity or quality of breast milk.

Q: All of the following are contraindications for the use of metformin, except?

Hypokalemia. **Explanation:** Metformin, a biguanide, is the first-line oral hypoglycemic agent for Type 2 Diabetes Mellitus. Its most serious, albeit rare, side effect is **Lactic Acidosis**. Therefore, its contraindications are primarily conditions that increase lactate production or decrease its clearance. **Why Hypokalemia is the Correct Answer:** Hypokalemia is **not** a contraindication for metformin. In fact, unlike insulin or beta-2 agonists which shift potassium intracellularly, metformin does not significantly affect serum potassium levels. Interestingly, other diabetes drugs like SGLT2 inhibitors or insulin may require monitoring of electrolytes, but metformin does not. **Why the other options are Contraindications:** * **Renal Failure (Option C):** This is the most important contraindication. Metformin is excreted unchanged by the kidneys. In renal impairment (eGFR <30 mL/min), the drug accumulates, significantly increasing the risk of lactic acidosis. * **Hypotensive State (Option A):** Conditions causing tissue hypoperfusion (shock, heart failure, or sepsis) lead to anaerobic metabolism and increased lactate production. Metformin inhibits gluconeogenesis from lactate, exacerbating this accumulation. * **Alcoholics (Option B):** Alcohol potentiates metformin’s effect on lactate metabolism by increasing the NADH/NAD+ ratio, which shifts the equilibrium toward lactate production, raising the risk of toxicity. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Activates AMP-activated protein kinase (AMPK), primarily reducing hepatic glucose production. * **Weight Neutrality:** Metformin is often associated with modest weight loss. * **Vitamin Deficiency:** Long-term use can lead to **Vitamin B12 deficiency** (megaloblastic anemia). * **Radiology Alert:** Metformin must be withheld for 48 hours after using **IV iodinated contrast** to prevent acute renal failure and subsequent lactic acidosis.

Question 1

Octreotide is not used in which of the following conditions?

Accepted Answer

Glucagonoma syndrome

Answer

Varices

Answer

Refractory diarrhoea in AIDS

Answer

Carcinoid syndrome

Question 2

Which of the following drugs does NOT produce gynecomastia?

Accepted Answer

Coisol

Answer

Cimetidine

Answer

Digoxin

Answer

Spironolactone

Question 3

Anti-inflammatory action of glucocorticoids is mainly due to which of the following mechanisms?

Accepted Answer

Increased annexin synthesis

Answer

Increased IL-2 production

Answer

Decreased arachidonic acid release

Answer

Decreased CRP levels

Question 4

Which of the following drugs does NOT cause gynecomastia?

Accepted Answer

Amiloride

Answer

Digoxin

Answer

Cimetidine

Answer

Ketoconazole

Question 5

Which of the following drugs inhibits spermatogenesis?

Accepted Answer

Gossypol

Answer

Gelusil

Answer

Gestodine

Answer

Gemcadiol

Question 6

Desmopressin can be used for all of the following conditions EXCEPT?

Accepted Answer

Nephrogenic diabetes insipidus

Answer

Neurogenic diabetes insipidus

Answer

Nocturnal enuresis (bed wetting) in children

Answer

Bleeding due to mild hemophilia A

Question 7

Which of the following is NOT an adverse drug reaction of metformin?

Accepted Answer

Weight gain

Answer

Diarrhea

Answer

Nausea

Answer

Lactic acidosis

Question 8

Which of the following drugs is administered in a pulsatile manner?

Accepted Answer

Goserelin

Answer

Octreotide

Answer

Abarelix

Answer

Aspirin

Question 9

Which one of the following is a non-steroidal contraceptive?

Accepted Answer

Centchroman

Answer

Mifepristone (RU-486)

Answer

Progestin-only pill (Minipill)

Answer

Norethisterone enanthate (NET-EN)

Question 10

All of the following are contraindications for the use of metformin, except?

Accepted Answer

Hypokalemia

Answer

Hypotensive state

Answer

Alcoholics

Answer

Renal failure

Endocrine Pharmacology — MCQs

Endocrine Pharmacology — MCQs

On this page

Practice by Chapter

Want unlimited practice?