Endocrine Pharmacology Practice Questions

Q: Which of the following statements about Mifepristone is FALSE?

It is a glucocorticoid receptor agonist.. **Explanation:** Mifepristone (RU-486) is a synthetic steroid compound with a high affinity for progesterone and glucocorticoid receptors. The correct answer is **Option C** because Mifepristone acts as a **glucocorticoid receptor antagonist**, not an agonist. At high doses, it blocks the action of cortisol, which is why it is also FDA-approved for managing hyperglycemia in patients with Cushing’s syndrome. **Analysis of Options:** * **Option A (True):** Mifepristone is primarily used for the medical termination of pregnancy (MTP). It sensitizes the myometrium to prostaglandins and causes decidual breakdown, leading to abortion. * **Option B (True):** It is classified as a Selective Progesterone Receptor Modulator (SPRM). It exhibits tissue-specific effects, primarily acting as an antagonist in the presence of progesterone. * **Option D (True):** In the endometrium, it acts as a competitive antagonist at the progesterone receptor level. This leads to the shedding of the decidua and prevents the maintenance of early pregnancy. **High-Yield Clinical Pearls for NEET-PG:** * **MTP Protocol:** The standard regimen is **200 mg Mifepristone (oral)** followed by **800 mcg Misoprostol (vaginal/oral/sublingual)** 24–48 hours later for pregnancies up to 63–70 days. * **Emergency Contraception:** A single dose of 10 mg Mifepristone is highly effective if taken within 120 hours of unprotected intercourse. * **Other Uses:** Management of uterine fibroids (reduces size), endometriosis, and induction of labor in intrauterine fetal death (IUFD). * **Contraindication:** Chronic ectopic pregnancy and patients on long-term corticosteroid therapy (due to its antiglucocorticoid action).

Q: Which of the following steroids possesses maximum glucocorticoid activity?

Dexamethasone. ### Explanation The potency of corticosteroids is determined by their affinity for glucocorticoid receptors (GR) versus mineralocorticoid receptors (MR). **Why Dexamethasone is Correct:** Dexamethasone is a long-acting, synthetic glucocorticoid. It is approximately **25 to 30 times more potent** than cortisol (hydrocortisone) in its anti-inflammatory and glucocorticoid effects. Crucially, it possesses **zero mineralocorticoid activity**, making it the drug of choice when high-dose steroid therapy is required without the risk of sodium and water retention. **Analysis of Incorrect Options:** * **A. Prednisolone:** This is an intermediate-acting steroid. It is about **4 times** more potent than cortisol but still retains some mineralocorticoid activity. * **B. Cortisol (Hydrocortisone):** This is the endogenous reference standard. It has a potency ratio of **1** and possesses significant mineralocorticoid activity (equal to its glucocorticoid activity). * **C. Aldosterone:** This is the primary endogenous **mineralocorticoid**. While it is a steroid, its glucocorticoid (anti-inflammatory) activity is negligible; its primary role is sodium retention and potassium excretion. **High-Yield NEET-PG Pearls:** 1. **Potency Hierarchy:** Dexamethasone = Betamethasone (25–30) > Methylprednisolone = Triamcinolone (5) > Prednisolone (4) > Hydrocortisone (1). 2. **Duration of Action:** Dexamethasone is **long-acting** (t½ > 36 hours), whereas Hydrocortisone is **short-acting** (t½ 8–12 hours). 3. **Clinical Use:** Dexamethasone is preferred in cerebral edema and for the **Dexamethasone Suppression Test (DST)** to diagnose Cushing’s syndrome because it does not interfere with endogenous cortisol assays. 4. **Fetal Lung Maturity:** Betamethasone and Dexamethasone are used in preterm labor because they cross the placenta and have low protein binding.

Q: All of the following drugs are oxytocics except?

Orciprenaline. **Explanation:** The question asks to identify the drug that is **not** an oxytocic. **Oxytocics** (Ecbolics) are drugs that stimulate uterine contractions, primarily used to induce labor or control postpartum hemorrhage (PPH). Conversely, **Tocolytics** are drugs that relax the uterus to delay preterm labor. **1. Why Orciprenaline is the correct answer:** Orciprenaline (Metaproterenol) is a **$\beta_2$-adrenergic agonist**. Activation of $\beta_2$ receptors in the myometrium increases intracellular cAMP, leading to uterine relaxation. Therefore, Orciprenaline is a **tocolytic**, not an oxytocic. It is primarily used to delay preterm labor or in cases of uterine hyperstimulation. **2. Why the other options are incorrect:** * **Oxytocin:** The drug of choice for induction of labor. It acts via G-protein coupled receptors to increase intracellular calcium, causing rhythmic uterine contractions. * **Ergometrine:** An ergot alkaloid that causes sustained (tetanic) uterine contractions. It is used exclusively postpartum to prevent or treat PPH and is contraindicated for induction of labor due to the risk of fetal asphyxia. * **Prostaglandins (e.g., PGE2, PGF2$\alpha$):** Drugs like Dinoprostone and Misoprostol are potent oxytocics used for cervical ripening, induction of labor, and management of PPH. **Clinical Pearls for NEET-PG:** * **Tocolytic Mnemonic (It’s Not My Time):** **I**ndomethacin (NSAID), **N**ifedipine (CCB - Drug of choice), **M**agnesium sulfate, **T**erbutaline/Ritodrine ($\beta_2$ agonists). * **Atosiban:** A specific oxytocin receptor antagonist used as a tocolytic. * **Ergotism:** Chronic poisoning with ergot alkaloids can lead to gangrene due to persistent vasoconstriction.

Q: Which of the following drugs is contraindicated in diabetic patients?

Steroids. **Explanation:** **Correct Option: B. Steroids** Glucocorticoids (Steroids) are potent **diabetogenic** drugs. They increase blood glucose levels through multiple mechanisms: 1. **Increased Gluconeogenesis:** They stimulate the liver to produce glucose from non-carbohydrate sources. 2. **Peripheral Insulin Resistance:** They decrease glucose uptake in skeletal muscle and adipose tissue by interfering with GLUT-4 translocation. 3. **Lipolysis:** They promote the breakdown of fats, increasing free fatty acids which further antagonize insulin action. In diabetic patients, steroid use can lead to severe hyperglycemia or even Diabetic Ketoacidosis (DKA). **Incorrect Options:** * **A. Mannitol:** An osmotic diuretic used primarily to reduce intracranial or intraocular pressure. While it is a sugar alcohol, it is not significantly metabolized to glucose and does not worsen glycemic control. * **C. Enalapril:** An ACE inhibitor. These are actually the **drugs of choice** for hypertensive diabetic patients because they provide **nephroprotection** by reducing efferent arteriolar resistance and slowing the progression of diabetic nephropathy. * **D. Glycerol:** Used as an osmotic agent (e.g., in glaucoma). While it can enter metabolic pathways, it does not pose the same systemic hyperglycemic risk as steroids in standard clinical doses. **High-Yield Clinical Pearls for NEET-PG:** * **Other Diabetogenic Drugs:** Thiazide diuretics, Beta-blockers (can mask hypoglycemia symptoms and worsen insulin resistance), Oral Contraceptives, and Phenytoin. * **Steroid-Induced Diabetes:** Typically presents with elevated postprandial glucose levels rather than fasting levels. * **DOC for Diabetes with HTN:** ACE inhibitors or ARBs (due to their ability to prevent/delay microalbuminuria).

Q: Which of the following drugs is both antiresorptive and bone formative?

Strontium ranelate. **Explanation:** **Strontium ranelate** is unique among osteoporosis treatments because of its **dual mechanism of action**. It is the only drug listed that acts as both an **antiresorptive** and a **bone-forming (anabolic)** agent. It works by: 1. **Increasing bone formation:** It stimulates the proliferation of osteoblasts and increases collagen synthesis. 2. **Decreasing bone resorption:** It inhibits the differentiation and activity of osteoclasts while promoting their apoptosis. This "uncoupling" of the bone remodeling process leads to a net increase in bone mineral density. **Analysis of Incorrect Options:** * **B. Calcitonin:** A pure **antiresorptive** agent. It directly inhibits osteoclast activity but does not stimulate new bone formation. It is primarily used for the acute management of hypercalcemia and Paget’s disease. * **C. Ibandronate:** A nitrogen-containing **Bisphosphonate**. These are potent **antiresorptive** drugs that induce osteoclast apoptosis. They do not have anabolic properties. * **D. Teriparatide:** A recombinant human PTH analogue. It is a pure **anabolic (bone-forming)** agent. When given in intermittent low doses, it stimulates osteoblast activity more than osteoclast activity. **NEET-PG High-Yield Pearls:** * **Strontium Ranelate Safety:** Its use has significantly declined due to an increased risk of **cardiovascular events** (myocardial infarction) and severe skin reactions (DRESS syndrome). * **Denosumab:** A monoclonal antibody against **RANKL**; it is a potent antiresorptive. * **Romosozumab:** A newer agent (Sclerostin inhibitor) that also shows dual action (increases formation and decreases resorption), often compared to Strontium in recent literature. * **Drug of Choice:** Bisphosphonates remain the first-line treatment for postmenopausal osteoporosis.

Q: Which of the following statements regarding Finasteride is true?

Used in androgenic alopecia. **Explanation:** **Finasteride** is a selective inhibitor of the **Type II 5-alpha reductase** enzyme. This enzyme is responsible for converting Testosterone into its more potent metabolite, **Dihydrotestosterone (DHT)**. 1. **Why Option A is Correct:** DHT is the primary androgen responsible for miniaturization of hair follicles in genetically predisposed individuals. By lowering scalp DHT levels, Finasteride effectively reverses the balding process. It is FDA-approved for **Androgenic Alopecia** (male pattern baldness) at a dose of 1 mg/day. 2. **Why Option B is technically "less correct" in this specific MCQ context:** While Finasteride does inhibit 5-alpha reductase, most competitive exams (like NEET-PG) prioritize the **clinical indication** over the mechanism if the question asks "which is true" and a specific therapeutic use is provided. Furthermore, Finasteride is selective for *Type II*, whereas Dutasteride inhibits both Type I and II. 3. **Why Option C is incorrect:** While Finasteride *can* cause decreased libido and erectile dysfunction as side effects, these occur in a small percentage of patients (<2%). In MCQ patterns, a primary clinical indication (Option A) is considered a more definitive "true" statement than a potential adverse effect. 4. **Why Option D is incorrect:** Undescended testes (Cryptorchidism) are typically managed surgically (Orchidopexy) or occasionally with hCG/GnRH analogues, not anti-androgens. **High-Yield Clinical Pearls for NEET-PG:** * **Indications:** Benign Prostatic Hyperplasia (BPH) at 5 mg/day and Androgenic Alopecia at 1 mg/day. * **Teratogenicity:** It is contraindicated in pregnancy (Category X) as it can cause feminization of a male fetus; even handling crushed tablets is avoided by pregnant women. * **Dutasteride:** A more potent, non-selective 5-alpha reductase inhibitor with a longer half-life.

Q: Therapeutic uses of calcium salts include the following, except:

Disorder of coagulation. **Explanation:** The correct answer is **Disorder of coagulation (Option B)**. While calcium ions ($Ca^{2+}$) are essential physiological cofactors in the coagulation cascade (Factor IV), exogenous administration of calcium salts has **no therapeutic role** in treating clinical bleeding disorders or coagulopathies. Deficiencies in clotting are managed by replacing specific clotting factors, platelets, or Vitamin K, as systemic hypocalcemia severe enough to impair coagulation is incompatible with life due to prior cardiac and neurological catastrophe. **Analysis of other options:** * **Osteoporosis (Option A):** Calcium supplements (often with Vitamin D) are a mainstay of treatment and prevention to maintain bone mineral density and reduce fracture risk [1]. * **Laryngospasm (Option C):** Hypocalcemia increases neuromuscular excitability (tetany). Laryngospasm is a life-threatening manifestation of severe hypocalcemia; intravenous calcium gluconate is the immediate treatment to stabilize the membrane. * **Extreme Hyperkalemia (Option D):** This is a critical "high-yield" use. Calcium (as Calcium Gluconate or Chloride) antagonizes the membrane-excitability effects of potassium on the myocardium, protecting the heart from arrhythmias. It does *not* lower serum potassium levels but stabilizes the cardiac membrane. **NEET-PG High-Yield Pearls:** 1. **Drug of Choice:** IV **Calcium Gluconate** is preferred over Calcium Chloride for peripheral administration because it is less caustic to veins and less likely to cause tissue necrosis if extravasated. 2. **Hyperkalemia Management:** Remember the "C-BIG-K" mnemonic. **C**alcium comes first for membrane stabilization, followed by **B**icarbonate/Beta-agonists, **I**nsulin + **G**lucose, and **K**ayexalate/Dialysis for removal. 3. **Toxicity:** Calcium must be administered cautiously in patients taking **Digoxin**, as hypercalcemia can precipitate digoxin toxicity (Stone Heart phenomenon).

Q: Which is a short-acting glucocorticoid?

Hydrocortisone. **Explanation:** Glucocorticoids are classified based on their duration of action, which correlates with their biological half-life and anti-inflammatory potency. **1. Why Hydrocortisone is correct:** **Hydrocortisone (Cortisol)** is the prototypical **short-acting** glucocorticoid. It has a biological half-life of **8–12 hours**. It possesses equal glucocorticoid (anti-inflammatory) and mineralocorticoid (salt-retaining) potency (1:1 ratio). Due to its short duration and balanced profile, it is the drug of choice for replacement therapy in adrenal insufficiency (Addison’s disease). **2. Analysis of Incorrect Options:** * **Dexamethasone:** This is a **long-acting** glucocorticoid with a biological half-life of **36–72 hours**. It is highly potent, has zero mineralocorticoid activity, and is used for cerebral edema and the Dexamethasone Suppression Test. * **Fludrocortisone:** This is a synthetic mineralocorticoid with very high salt-retaining potency. While it has some glucocorticoid activity, it is classified and used clinically as a **mineralocorticoid** for replacement in Addison’s disease. * **Aldosterone:** This is the primary endogenous **mineralocorticoid** produced by the zona glomerulosa. It has negligible glucocorticoid activity and a very short half-life (approx. 20 minutes), making it unsuitable for therapeutic use as a glucocorticoid. **High-Yield NEET-PG Pearls:** * **Short-acting (8–12h):** Hydrocortisone, Cortisone. * **Intermediate-acting (12–36h):** Prednisolone, Methylprednisolone, Triamcinolone. * **Long-acting (36–72h):** Dexamethasone, Betamethasone. * **Potency Tip:** Dexamethasone is ~25 times more potent as an anti-inflammatory than Hydrocortisone. * **Pregnancy:** Prednisolone is preferred in pregnancy as it is inactivated by placental 11β-HSD2; Betamethasone/Dexamethasone are used to accelerate **fetal lung maturity** as they cross the placenta.

Question 1

Which of the following statements about Mifepristone is FALSE?

Accepted Answer

It is a glucocorticoid receptor agonist.

Answer

It is used for induction of abortion.

Answer

It is a selective progesterone receptor modulator.

Answer

It is a progesterone receptor antagonist in the endometrium.

Question 2

Which of the following steroids possesses maximum glucocorticoid activity?

Accepted Answer

Dexamethasone

Answer

Prednisolone

Answer

Cortisol

Answer

Aldosterone

Question 3

All of the following drugs are oxytocics except?

Accepted Answer

Orciprenaline

Answer

Oxytocin

Answer

Ergometrine

Answer

Prostaglandin

Question 4

Which of the following drugs is contraindicated in diabetic patients?

Accepted Answer

Steroids

Answer

Mannitol

Answer

Enalapril

Answer

Glycerol

Question 5

Which of the following drugs is both antiresorptive and bone formative?

Accepted Answer

Strontium ranelate

Answer

Calcitonin

Answer

Ibandronate

Answer

Teriparatide

Question 6

Mifepristone (RU-486) is:

Accepted Answer

Anti-progestin

Answer

Anti-androgen

Answer

Anti-estrogen

Answer

Androgen

Question 7

Which of the following statements regarding Finasteride is true?

Accepted Answer

Used in androgenic alopecia

Answer

Inhibits 5-alpha reductase

Answer

Can cause loss of libido

Answer

Used in undescended testes

Question 8

Therapeutic uses of calcium salts include the following, except:

Accepted Answer

Disorder of coagulation

Answer

Osteoporosis

Answer

Laryngospasm

Answer

Extreme hyperkalemia

Question 9

Which is a short-acting glucocorticoid?

Accepted Answer

Hydrocortisone

Answer

Fludrocortisone

Answer

Dexamethasone

Answer

Aldosterone

Question 10

Which of the following drugs can be used to suppress lactation?

Accepted Answer

Metoclopramide

Answer

Cabergoline

Answer

Pyridoxine

Answer

High dose estrogens

Endocrine Pharmacology — MCQs

Endocrine Pharmacology — MCQs

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