Endocrine Pharmacology Practice Questions

Q: Compared to hydrocortisone, which of the following has the maximum glucocorticoid activity?

Dexamethasone. ### Explanation The potency of corticosteroids is determined by their relative **glucocorticoid** (anti-inflammatory) and **mineralocorticoid** (salt-retaining) activities. Hydrocortisone (cortisol) is used as the standard reference with a potency ratio of 1:1. **Why Dexamethasone is Correct:** Dexamethasone is a long-acting synthetic glucocorticoid. It has the highest anti-inflammatory potency among the options provided, being approximately **25 to 30 times more potent than hydrocortisone**. Crucially, it possesses **zero mineralocorticoid activity**, making it ideal for conditions where fluid retention must be avoided (e.g., cerebral edema). **Analysis of Incorrect Options:** * **Cortisone:** This is a prodrug that must be converted to cortisol in the liver. It is actually *less* potent than hydrocortisone (0.8x potency). * **Prednisolone:** An intermediate-acting steroid with approximately **4 times** the anti-inflammatory potency of hydrocortisone. It retains some mineralocorticoid activity. * **Methylprednisolone:** Also an intermediate-acting steroid, it is slightly more potent than prednisolone, with approximately **5 times** the potency of hydrocortisone. **High-Yield NEET-PG Pearls:** 1. **Potency Hierarchy:** Dexamethasone = Betamethasone (25–30x) > Methylprednisolone (5x) > Prednisolone (4x) > Hydrocortisone (1x) > Cortisone (0.8x). 2. **Duration of Action:** Dexamethasone is **long-acting** (t½: 36–72 hours), whereas Prednisolone is intermediate-acting (t½: 12–36 hours). 3. **DOC for Fetal Lung Maturity:** Betamethasone or Dexamethasone are preferred because they poorly bind to transcortin and cross the placenta in active forms. 4. **Mineralocorticoid Powerhouse:** Fludrocortisone has the highest mineralocorticoid activity and is used in Addison’s disease.

Q: Biguanides act by which of the following mechanisms, except?

Stimulating insulin release from the pancreas. **Explanation:** **Biguanides (e.g., Metformin)** are classified as **euglycemic agents** or insulin sensitizers. Unlike Sulfonylureas and Meglitinides, they do not stimulate the pancreas to produce more insulin. **1. Why Option A is the Correct Answer (The "Except"):** Metformin does not act on the pancreatic beta cells to stimulate insulin secretion. Therefore, it does not cause hyperinsulinemia or hypoglycemia when used as monotherapy. This is the fundamental distinction between biguanides and "insulin secretagogues." **2. Analysis of Other Options:** * **Inhibiting Gluconeogenesis (Option C):** This is the **primary mechanism** of Metformin. It activates AMP-activated protein kinase (AMPK), which suppresses hepatic glucose production (gluconeogenesis) and glycogenolysis. * **Enhancing Insulin Binding (Option D):** Metformin increases the sensitivity of peripheral tissues (muscle and fat) to insulin by improving receptor binding and increasing the translocation of glucose transporters (GLUT-4) to the cell membrane. * **Promoting Glycolysis (Option B):** By activating AMPK, Metformin enhances anaerobic glycolysis in the tissues, which increases the peripheral utilization of glucose. **Clinical Pearls for NEET-PG:** * **Drug of Choice:** Metformin is the first-line drug for Type 2 Diabetes Mellitus, especially in obese patients, as it promotes modest weight loss. * **Adverse Effects:** The most common side effects are GI-related (diarrhea, metallic taste). The most serious, though rare, is **Lactic Acidosis** (due to inhibition of gluconeogenesis from lactate). * **Vitamin Deficiency:** Long-term use can lead to **Vitamin B12 deficiency** due to malabsorption. * **Contraindication:** It is contraindicated in patients with significant renal impairment (eGFR <30 mL/min) due to the risk of lactic acidosis.

Q: Pramlintide is?

Synthetic amylin analogue. **Explanation:** **Pramlintide** is a synthetic analogue of **Amylin**, a peptide hormone co-secreted with insulin by the pancreatic beta cells. In patients with Type 1 and Type 2 Diabetes, amylin levels are deficient. Pramlintide works by mimicking amylin’s physiological actions: it slows gastric emptying, suppresses postprandial glucagon secretion, and increases satiety (centrally mediated). It is notably the only non-insulin drug approved for use in **Type 1 Diabetes**, though it is also used in Type 2 Diabetes. **Analysis of Incorrect Options:** * **Option B (Inhibitor of DPP-4):** These are the "Gliptins" (e.g., Sitagliptin, Vildagliptin). They act by preventing the breakdown of endogenous GLP-1 and GIP. * **Option C (GLP-1 analogue):** These are the "Tides" (e.g., Exenatide, Liraglutide). While they share some effects with Pramlintide (like slowed gastric emptying), they primarily act by stimulating glucose-dependent insulin secretion. * **Option D (PPAR gamma):** This is the molecular target for **Thiazolidinediones** (e.g., Pioglitazone), which act as insulin sensitizers in peripheral tissues. **High-Yield Clinical Pearls for NEET-PG:** * **Route:** Administered via **subcutaneous injection** immediately before meals. * **Key Side Effect:** Severe **hypoglycemia** (when used with insulin) and nausea. * **Contraindication:** Gastroparesis (due to its effect on slowing gastric motility). * **Weight Effect:** It is associated with **weight loss**, making it beneficial for obese diabetic patients.

Q: Which of the following medications can be safely used in pregnancy?

Propylthiouracil. **Explanation:** **Propylthiouracil (PTU)** is the drug of choice for managing hyperthyroidism during the **first trimester** of pregnancy. While both PTU and Methimazole cross the placenta, PTU is more extensively protein-bound, leading to less placental transfer. More importantly, Methimazole is avoided in early pregnancy due to its association with **choanal atresia** and **aplasia cutis** (Methimazole embryopathy). PTU is preferred initially, though many clinicians switch to Methimazole in the second and third trimesters to avoid PTU-induced maternal hepatotoxicity. **Incorrect Options:** * **ACE Inhibitors (e.g., Enalapril) & AT Receptor Antagonists (ARBs, e.g., Losartan):** Both are strictly contraindicated (Category X/D) throughout pregnancy, especially in the 2nd and 3rd trimesters. They interfere with fetal renal development, leading to **oligohydramnios**, fetal renal failure, hypocalvaria (skull defects), and pulmonary hypoplasia. * **Aldosterone:** While not a standard medication, mineralocorticoid antagonists (like Spironolactone) are generally avoided due to potential anti-androgenic effects on the developing male fetus. **NEET-PG High-Yield Pearls:** * **Safe Antihypertensives in Pregnancy:** Remember the mnemonic **"Better Mother Care During Hypertensive"** (B-Blockers/Labetalol, Methyldopa, Calcium Channel Blockers/Nifedipine, Hydralazine). * **Methyldopa** is the traditional drug of choice for chronic hypertension in pregnancy. * **Labetalol** is currently preferred for acute management of hypertensive emergencies in pregnancy. * **Teratogenic effect of Methimazole:** Aplasia cutis (congenital focal absence of skin).

Q: Which of the following is a long-acting glucocorticoid?

Dexamethasone. **Explanation:** Glucocorticoids are classified based on their duration of action (biological half-life), which correlates with their anti-inflammatory potency and mineralocorticoid (salt-retaining) activity. **1. Why Dexamethasone is Correct:** **Dexamethasone** is a **long-acting** glucocorticoid with a biological half-life of **36–54 hours**. It is highly potent (about 25–30 times more potent than hydrocortisone) and possesses negligible mineralocorticoid activity. This makes it ideal for conditions requiring sustained suppression of inflammation or the immune system, such as cerebral edema or as a diagnostic tool in the Dexamethasone Suppression Test (DST). **2. Why the Other Options are Incorrect:** * **Hydrocortisone (Option D):** This is a **short-acting** glucocorticoid (half-life 8–12 hours). It is the pharmaceutical form of cortisol and has significant mineralocorticoid activity, making it the drug of choice for replacement therapy in adrenal insufficiency. * **Prednisolone (Option C):** This is an **intermediate-acting** glucocorticoid (half-life 18–36 hours). It is commonly used for chronic inflammatory and autoimmune conditions. * **Triamcinolone (Option B):** Also an **intermediate-acting** steroid. It is notable for having zero mineralocorticoid activity and is frequently used in topical or intra-articular preparations. **NEET-PG High-Yield Pearls:** * **Potency Rule:** As the duration of action increases, anti-inflammatory potency increases, while mineralocorticoid activity decreases. * **Betamethasone:** Another long-acting steroid; it is specifically used to accelerate **fetal lung maturity** in preterm labor because it crosses the placental barrier and has low protein binding. * **Mnemonic for Duration:** * **Short:** Hydrocortisone, Cortisone. * **Intermediate:** Prednisolone, Triamcinolone, Methylprednisolone. * **Long:** Dexamethasone, Betamethasone.

Q: Danazol is not used in which of the following conditions?

Endometrial carcinoma. **Explanation:** **Danazol** is a synthetic ethisterone derivative with mild androgenic and strong anti-gonadotropic properties. It acts primarily by inhibiting the pituitary-ovarian axis (suppressing LH and FSH surges) and creating a hypoestrogenic, hyperandrogenic environment. **Why Endometrial Carcinoma is the correct answer:** Danazol has no role in the management of **Endometrial Carcinoma**. The primary hormonal treatment for advanced or recurrent endometrial carcinoma involves high-dose **progestogens** (like Megestrol acetate) or GnRH agonists, which counteract the estrogen-driven growth of the tumor. Danazol’s androgenic profile does not provide the necessary therapeutic effect for malignant transformation of the endometrium. **Analysis of Incorrect Options:** * **Precocious Puberty:** Danazol can be used to suppress the premature surge of gonadotropins, thereby delaying the onset of puberty and preventing premature epiphyseal closure. * **Endometriosis:** This is the classic indication for Danazol. It induces "pseudomenopause" by inhibiting ovulation and directly suppressing endometrial tissue growth, leading to atrophy of ectopic implants. * **Dysfunctional Uterine Bleeding (DUB):** Danazol is effective in reducing menstrual blood loss by causing endometrial atrophy. It is often used as a second-line medical therapy when NSAIDs or antifibrinolytics fail. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** It creates a "pseudomenopause" state. * **Other Indications:** Fibrocystic breast disease, Hereditary Angioneurotic Edema (increases C4 component of complement), and Autoimmune Hemolytic Anemia. * **Side Effects:** Weight gain, acne, hirsutism, deepening of voice (often irreversible), and oiliness of skin. * **Contraindications:** Pregnancy (teratogenic—causes virilization of female fetus), breastfeeding, and severe hepatic impairment.

Q: Which of the following drugs is used to treat both diabetes mellitus and diabetes insipidus?

Chlorpropamide. **Explanation:** **Chlorpropamide** is a first-generation sulfonylurea that is unique because it possesses clinical utility in both Diabetes Mellitus (DM) and Central Diabetes Insipidus (DI). 1. **Mechanism in Diabetes Mellitus:** Like other sulfonylureas, it stimulates insulin release from pancreatic beta cells by blocking ATP-sensitive potassium channels ($K_{ATP}$), leading to depolarization and calcium influx. 2. **Mechanism in Diabetes Insipidus:** Chlorpropamide treats Central DI through two mechanisms: * It sensitizes the renal collecting ducts to the action of endogenous Antidiuretic Hormone (ADH/Vasopressin). * It may stimulate a modest increase in the release of ADH from the posterior pituitary. * *Note:* It is ineffective in Nephrogenic DI because the renal receptors are non-functional. **Why other options are incorrect:** * **Glibenclamide, Gliclazide, and Glipizide:** These are second-generation sulfonylureas. While they are significantly more potent than chlorpropamide for treating Type 2 DM, they lack the ADH-sensitizing effect required to treat Diabetes Insipidus. **High-Yield Clinical Pearls for NEET-PG:** * **Disulfiram-like reaction:** Chlorpropamide is notorious for causing a disulfiram-like reaction when consumed with alcohol. * **Dilutional Hyponatremia:** Due to its ADH-potentiating effect (SIADH-like picture), chlorpropamide can cause significant hyponatremia, especially in elderly patients. * **Longest Half-life:** It has the longest duration of action among sulfonylureas, increasing the risk of prolonged hypoglycemia. * **Other drugs for DI:** Thiazides (Paradoxical effect in Nephrogenic DI), Amiloride (Lithium-induced DI), and Desmopressin (Drug of choice for Central DI).

Q: Which oral hypoglycemic drug is least likely to cause hypoglycemia?

Rosiglitazone. ### Explanation The risk of hypoglycemia with oral hypoglycemic agents (OHAs) depends primarily on whether the drug’s mechanism is **insulin-independent** or **insulin-secretagogue** based. **1. Why Rosiglitazone is the Correct Answer:** Rosiglitazone belongs to the **Thiazolidinedione (TZD)** class. These drugs act as agonists for the **PPAR-γ receptor**, which increases peripheral insulin sensitivity (primarily in adipose tissue, muscle, and liver). Because TZDs do not stimulate the pancreas to release more insulin but rather make existing insulin work more efficiently, they are considered **"euglycemic"** agents. They do not cause hypoglycemia when used as monotherapy. **2. Why the Other Options are Incorrect:** * **Gliclazide & Glimepiride (Options B & D):** These are **Sulfonylureas**. They act by closing ATP-sensitive K⁺ channels in pancreatic beta cells, leading to depolarization and forced insulin secretion regardless of blood glucose levels. Hypoglycemia is their most common and significant side effect. * **Repaglinide (Option A):** This is a **Meglitinide** (Glinide). Like sulfonylureas, it is an insulin secretagogue. Although it has a shorter duration of action and is taken pre-prandially, it still carries a distinct risk of hypoglycemia if a meal is delayed or skipped. **3. NEET-PG High-Yield Pearls:** * **Weight Gain:** Both TZDs and Sulfonylureas cause weight gain, but via different mechanisms (TZDs cause fluid retention and fat redistribution; Sulfonylureas are anabolic due to high insulin). * **TZD Side Effects:** Watch for **fluid retention/edema** (contraindicated in CHF), **bone fractures** (osteoporosis risk), and bladder cancer (specifically associated with Pioglitazone). * **Drug of Choice:** Metformin (a Biguanide) is also an insulin sensitizer and, like TZDs, has a very low risk of hypoglycemia, making it the first-line treatment for Type 2 Diabetes.

Question 1

Compared to hydrocortisone, which of the following has the maximum glucocorticoid activity?

Accepted Answer

Dexamethasone

Answer

Cortisone

Answer

Prednisolone

Answer

Methylprednisolone

Question 2

Biguanides act by which of the following mechanisms, except?

Accepted Answer

Stimulating insulin release from the pancreas

Answer

Promoting glycolysis

Answer

Inhibiting gluconeogenesis

Answer

Enhancing insulin binding to its receptors

Question 3

Pramlintide is?

Accepted Answer

Synthetic amylin analogue

Answer

Inhibitor of DPP 4

Answer

GLP 1 analogue

Answer

PPAR gamma

Question 4

Calcitonin is used in all of the following conditions, EXCEPT:

Accepted Answer

Fanconi syndrome

Answer

Hypervitaminosis D

Answer

Postmenopausal osteoporosis

Answer

Paget's disease

Question 5

Which of the following medications can be safely used in pregnancy?

Accepted Answer

Propylthiouracil

Answer

ACE inhibitors

Answer

Aldosterone

Answer

AT receptor antagonist

Question 6

Which of the following is a long-acting glucocorticoid?

Accepted Answer

Dexamethasone

Answer

Triamcinolone

Answer

Prednisolone

Answer

Hydrocortisone

Question 7

Danazol is not used in which of the following conditions?

Accepted Answer

Endometrial carcinoma

Answer

Precocious puberty

Answer

Endometriosis

Answer

Dysfunctional uterine bleeding (DUB)

Question 8

Which of the following drugs is used to treat both diabetes mellitus and diabetes insipidus?

Accepted Answer

Chlorpropamide

Answer

Glibenclamide

Answer

Glicazide

Answer

Glipizide

Question 9

Which oral hypoglycemic drug is least likely to cause hypoglycemia?

Accepted Answer

Rosiglitazone

Answer

Repaglinide

Answer

Gliclazide

Answer

Glimipiride

Question 10

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

Accepted Answer

Dexamethasone

Answer

Betamethasone

Answer

Hydrocortisone

Answer

Prednisolone

Endocrine Pharmacology — MCQs

Endocrine Pharmacology — MCQs

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