Endocrine Pharmacology Practice Questions

Q: Which of the following drugs can prevent the peripheral conversion of T4 to T3?

Propylthiouracil. ***Propylthiouracil*** - Propylthiouracil (PTU) is a **thionamide drug** that inhibits thyroid peroxidase, thereby blocking the synthesis of thyroid hormones. - Additionally, PTU specifically inhibits the **5'-deiodinase enzyme**, which is responsible for the peripheral conversion of **thyroxine (T4)** to the more active **triiodothyronine (T3)**. - This is a **unique property** of PTU that distinguishes it from methimazole, making it preferred in thyrotoxic storm. *Propranolol* - Propranolol is a **beta-blocker** primarily used to alleviate the **symptomatic effects** of hyperthyroidism, such as palpitations, tremor, and anxiety. - Although high doses may have a minor effect on T4 to T3 conversion, this is **not clinically significant** and not the reason for its use in thyroid disorders. *Iodides* - High doses of iodides, such as **potassium iodide**, can acutely inhibit thyroid hormone release (the **Wolff-Chaikoff effect**) and decrease thyroid gland vascularity. - Iodides do **not prevent the peripheral conversion of T4 to T3**; their main action is on hormone synthesis and release from the thyroid gland itself. *a and b both* - This option is incorrect because neither propranolol nor iodides have a clinically significant effect on inhibiting peripheral 5'-deiodinase enzyme. - Only **propylthiouracil** has this specific and therapeutically relevant action.

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

Betamethasone. **Betamethasone** - **Betamethasone** is classified as a **long-acting corticosteroid** with a duration of action greater than 36 hours. - Its prolonged action is due to its chemical structure, which allows for slower metabolism and excretion. *Triamcinolone* - **Triamcinolone** is an **intermediate-acting corticosteroid** with a duration of action typically between 12 to 36 hours. - It is often used for conditions requiring an effect longer than hydrocortisone but shorter than the ultra-long acting corticosteroids. *Hydrocortisone* - **Hydrocortisone** is a **short-acting corticosteroid**, with a duration of action of 8-12 hours. - It is equivalent to the natural hormone **cortisol** and is primarily used for replacement therapy or conditions requiring a rapid, short-term effect. *Prednisolone* - **Prednisolone** is an **intermediate-acting corticosteroid**, similar to triamcinolone, with a duration of action between 12 to 36 hours [1]. - It is frequently used for inflammatory and autoimmune conditions due to its potent anti-inflammatory effects.

Q: Which of the following actions are associated with Danazol?

All of the options. ***All of the options*** - **Danazol** is a synthetic steroid with a variety of hormonal activities, including **weak androgenic**, **anabolic**, and **progestational** effects. - Its diverse pharmacological profile contributes to its therapeutic uses, particularly in conditions like **endometriosis** and **fibrocystic breast disease**, where it suppresses gonadotropin release and ovarian function. - All three properties listed (androgenic, progestational, and anabolic) are characteristics of Danazol. **Weak androgenic activity:** - Danazol possesses **weak androgenic activity**, meaning it can bind to androgen receptors and exert effects similar to, but less potent than, testosterone. - This can lead to side effects such as **hirsutism**, **acne**, and **voice deepening** in some patients. **Progestational activity:** - While not its primary action, Danazol has some **progestational properties** due to its steroid structure, contributing to its ability to suppress the hypothalamic-pituitary-ovarian axis. - This activity helps in creating a **hypoestrogenic state**, which is beneficial in treating conditions like endometriosis. **Anabolic activity:** - Danazol has **anabolic effects**, promoting protein synthesis and muscle growth, similar to other anabolic steroids. - This property is utilized in treating **hereditary angioedema** by increasing C1 esterase inhibitor levels. - This can lead to side effects like **weight gain** and changes in **lipid profiles**.

Q: HbA1C is decreased most by?

Biguanides. ***Biguanides***- **Metformin**, the primary biguanide, is considered a first-line agent for type 2 diabetes and can significantly lower **HbA1c** by 1.0-2.0% [1].- It primarily works by decreasing hepatic **glucose production** and increasing **insulin sensitivity** in peripheral tissues [1].*Sulfonylureas*- Sulfonylureas stimulate **insulin release** from pancreatic beta cells, thereby lowering blood glucose.- They typically decrease **HbA1c** by 1.0-2.0%, similar to biguanides, but are associated with a higher risk of **hypoglycemia** and weight gain.*Thiazolidinediones*- Thiazolidinediones (TZDs) improve **insulin sensitivity** in peripheral tissues and reduce hepatic glucose production [1].- They reduce **HbA1c** by approximately 0.5-1.5% but have a slower onset of action and are associated with side effects like **fluid retention** and weight gain [1].*Acarbose*- Acarbose is an **alpha-glucosidase inhibitor** that delays the absorption of carbohydrates in the small intestine, primarily reducing postprandial glucose excursions [2].- Its effect on **HbA1c** is more modest, typically lowering it by 0.5-0.8%, making it less potent for overall long-term glucose control compared to other agents.

Q: A middle-aged male patient presents with protrusion of the chin, excessive sweating, impaired glucose tolerance, and enlargement of hands and feet. Which of the following is a growth hormone receptor antagonist used to treat this condition?

Pegvisomant. ***Pegvisomant*** - **Pegvisomant** is a **growth hormone receptor antagonist** that binds to growth hormone receptors, preventing endogenous growth hormone from signaling and reducing IGF-1 levels. - It is specifically used in the treatment of **acromegaly**, a condition characterized by excessive growth hormone secretion, which aligns with the patient's symptoms of chin protrusion, excessive sweating, impaired glucose tolerance, and enlarged hands and feet. *Octreotide* - **Octreotide** is a **somatostatin analog** that works by inhibiting growth hormone secretion from the pituitary gland. - While used in acromegaly, it is not a growth hormone receptor antagonist, but rather reduces the production of growth hormone itself. *Cabergoline* - **Cabergoline** is a **dopamine agonist** primarily used to treat hyperprolactinemia by inhibiting prolactin secretion. - It can sometimes be used in acromegaly for patients with co-secretion of prolactin or those who are sensitive to its effects on growth hormone, but it is not a direct growth hormone receptor antagonist. *Olcegepant* - **Olcegepant** is a **calcitonin gene-related peptide (CGRP) receptor antagonist** developed for the treatment of migraine. - It has no known therapeutic role in the management of acromegaly or growth hormone-related disorders.

Q: Misoprostol used in the induction of labour is an analogue of which of the following type of prostaglandin?

PG E1. ***PG E1*** - **Misoprostol** is a synthetic analogue of **prostaglandin E1 (PGE1)**, which is used for cervical ripening and uterine contractions in labor induction. - PGE1 analogues help to soften the cervix, increase its compliance, and stimulate uterine smooth muscle contraction. *PG E2* - **Dinoprostone** is a synthetic analogue of **prostaglandin E2 (PGE2)**, commonly used for cervical ripening and induction of labor. - While PGE2 also induces labor, misoprostol specifically mimics the actions of PGE1. *PG I2* - **Prostacyclin (PGI2)** is primarily known for its role in inhibiting platelet aggregation and causing vasodilation. - It is not routinely used for labor induction due to its primary vascular effects and lack of direct uterine contractile properties at relevant doses. *PG F2alpha* - **Prostaglandin F2-alpha (PGF2α)**, such as **carboprost**, is used for postpartum hemorrhage to cause strong uterine contractions. - While it causes uterine contractions, its primary obstetric use is not for labor induction but rather for stimulating aggressive uterine contraction to stop bleeding.

Q: What is the first-line drug for osteoporosis in postmenopausal women?

Bisphosphonates. ***Bisphosphonates*** - **Bisphosphonates** are the **first-line treatment** for osteoporosis in postmenopausal women due to their proven efficacy in reducing the risk of fragility fractures. - They work by **inhibiting osteoclast activity**, thereby decreasing bone turnover and increasing bone mineral density. *Oral Contraceptive Pills* - **Oral contraceptive pills** are primarily used for contraception and managing menstrual irregularities; they are **not a treatment for established osteoporosis**. - While estrogen plays a role in bone health, the focus for osteoporosis treatment is on anti-resorptive or anabolic agents. *Strontium* - **Strontium ranelate** has been used in some countries for osteoporosis, but its use is **limited due to concerns about cardiovascular adverse events** and is not typically a first-line drug. - It has a dual mechanism of action, both decreasing bone resorption and increasing bone formation. *Selective Estrogen Receptor Modulator (SERM)* - **SERMs**, such as **raloxifene**, are indicated for the prevention and treatment of osteoporosis, particularly in women with a high risk of **breast cancer**, but they are **not considered first-line** for all postmenopausal women compared to bisphosphonates. - They act as estrogen agonists in bone but are antagonists in breast and uterine tissue.

Q: Which of the following drugs is used in SIADH?

Tolvaptan. ***Tolvaptan*** - **Tolvaptan** is a **vasopressin receptor antagonist** that blocks the action of **antidiuretic hormone (ADH)** at the **V2 receptors** in the kidneys [1]. - This action promotes **water excretion (aquaresis)** without significantly affecting electrolyte balance, thereby increasing serum sodium levels in patients with **SIADH** [1]. *Desmopressin* - **Desmopressin** is a synthetic analog of **ADH** that primarily acts on **V2 receptors**, promoting water reabsorption [3], [4]. - It is used in conditions like **diabetes insipidus** [3], [4] or **hemophilia** [2] to increase ADH activity or clotting factors, which is contrary to the goal in SIADH. *Von Willebrand factor* - **Von Willebrand factor** is a **glycoprotein** involved in **hemostasis**, promoting platelet adhesion and carrying **factor VIII**. - It plays no role in the direct management of **SIADH** or fluid balance disorders. *Terlipressin* - **Terlipressin** is an analog of **vasopressin** that primarily acts on **V1 receptors**, causing vasoconstriction [5]. - It is used in conditions like **hepatorenal syndrome** or **esophageal variceal bleeding**, not for treating **SIADH**.

Q: Which drug decreases the bone resorption in osteoporosis?

Risedronate. ***Risedronate*** - **Risedronate** is a **bisphosphonate**, a class of drugs that inhibits osteoclast activity, thereby decreasing **bone resorption**. - By reducing the rate at which bone is broken down, it helps to preserve **bone mineral density** in patients with osteoporosis. *Teriparatide* - **Teriparatide** is a **parathyroid hormone analog** that primarily works by stimulating **osteoblast activity** to promote new bone formation. - While it treats osteoporosis, its primary mechanism is **anabolic** (bone building), not directly decreasing bone resorption as its main effect. *Cortisone* - **Cortisone** is a **glucocorticoid** that can actually *worsen* osteoporosis by increasing **bone resorption** and decreasing **bone formation** with long-term use. - It is used to treat inflammatory conditions, not to decrease bone resorption for osteoporosis. *Cimetidine* - **Cimetidine** is an **H2-receptor antagonist** used to reduce stomach acid production, commonly for conditions like GERD or ulcers. - It has no known effect on **bone metabolism** or **osteoporosis**.

Question 1

Which of the following drugs can prevent the peripheral conversion of T4 to T3?

Accepted Answer

Propylthiouracil

Answer

Propranolol

Answer

Iodides

Answer

a and b both

Question 2

Which of the following is a long-acting corticosteroid?

Accepted Answer

Betamethasone

Answer

Triamcinolone

Answer

Hydrocortisone

Answer

Prednisolone

Question 3

Which of the following actions are associated with Danazol?

Accepted Answer

All of the options

Answer

Weak androgenic

Answer

Progestational

Answer

Anabolic

Question 4

HbA1C is decreased most by?

Accepted Answer

Biguanides

Answer

Thiazolidinediones

Answer

Sulfonylureas

Answer

Acarbose

Question 5

A middle-aged male patient presents with protrusion of the chin, excessive sweating, impaired glucose tolerance, and enlargement of hands and feet. Which of the following is a growth hormone receptor antagonist used to treat this condition?

Accepted Answer

Pegvisomant

Answer

Olcegepant

Answer

Cabergoline

Answer

Octreotide

Question 6

A female patient presents to the emergency department with severe restlessness, palpitations,    and tremors. She is a known case of bronchial asthma. On examination, the neck looks    swollen. Blood pressure is elevated, and tachycardia is noted. ECG shows atrial fibrillation.    Which of the following drugs is used for immediate management in this patient?

Accepted Answer

Esmolol

Answer

Diltiazem

Answer

Propranolol

Answer

Propylthiouracil

Question 7

Misoprostol used in the induction of labour is an analogue of which of the following type of prostaglandin?

Accepted Answer

PG E1

Answer

PG E2

Answer

PG I2

Answer

PG F2alpha

Question 8

What is the first-line drug for osteoporosis in postmenopausal women?

Accepted Answer

Bisphosphonates

Answer

Strontium

Answer

Oral Contraceptive Pills

Answer

Selective Estrogen Receptor Modulator (SERM)

Question 9

Which of the following drugs is used in SIADH?

Accepted Answer

Tolvaptan

Answer

Desmopressin

Answer

Terlipressin

Answer

Von Willebrand factor

Question 10

Which drug decreases the bone resorption in osteoporosis?

Accepted Answer

Risedronate

Answer

Teriparatide

Answer

Cortisone

Answer

Cimetidine

Endocrine Pharmacology — MCQs

Endocrine Pharmacology — MCQs

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