Endocrine Pharmacology Practice Questions

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.

Q: Thiazolidinedione is associated with an increased risk of?

Heart failure. **Explanation:** **Thiazolidinediones (TZDs)**, such as Pioglitazone and Rosiglitazone, are PPAR-γ (Peroxisome Proliferator-Activated Receptor gamma) agonists. The primary mechanism behind the increased risk of **Heart Failure** is their effect on the kidneys. Activation of PPAR-γ receptors in the collecting ducts leads to increased sodium and water reabsorption. This results in **fluid retention and peripheral edema**, which can precipitate or exacerbate congestive heart failure (CHF) in susceptible patients. Consequently, TZDs are contraindicated in patients with NYHA Class III or IV heart failure. **Analysis of Incorrect Options:** * **B. Pulmonary fibrosis:** This is a classic side effect of drugs like Amiodarone, Bleomycin, and Methotrexate, but it is not associated with TZDs. * **C. Myocarditis:** This is an inflammatory condition of the heart muscle, often viral or drug-induced (e.g., Clozapine), but not a known complication of TZD therapy. * **D. Renal dysfunction:** TZDs do not typically cause renal failure; in fact, they are generally safe to use in patients with mild-to-moderate renal impairment (unlike Metformin), though the associated fluid retention must be monitored. **High-Yield Clinical Pearls for NEET-PG:** * **Pioglitazone & Bladder Cancer:** Long-term use of Pioglitazone has been linked to an increased risk of urinary bladder cancer. * **Bone Health:** TZDs increase the risk of **osteoporosis and fractures**, particularly in postmenopausal women, by diverting mesenchymal stem cells away from osteoblast formation toward adipocyte formation. * **Weight Gain:** TZDs typically cause weight gain due to both fluid retention and the proliferation of subcutaneous fat. * **Rosiglitazone:** Historically restricted due to concerns regarding increased risk of myocardial infarction (though restrictions were later eased).

Q: Which of the following drugs or conditions does not cause hyperprolactinemia?

Bromocriptine. **Explanation** The regulation of prolactin is unique because it is under tonic **inhibitory** control by the hypothalamus. The primary prolactin-inhibiting factor (PIF) is **Dopamine**, which acts on **D2 receptors** in the anterior pituitary to suppress prolactin release. **Why Bromocriptine is the correct answer:** Bromocriptine is a potent **D2-receptor agonist**. By mimicking the action of dopamine, it directly inhibits the secretion of prolactin. Therefore, it is used therapeutically to treat hyperprolactinemia and prolactinomas, rather than causing the condition. **Analysis of Incorrect Options:** * **Levodopa:** While Levodopa is a precursor to dopamine, its effect on prolactin is transient and inconsistent in clinical practice. However, in the context of this specific question, it is often grouped with drugs that *reduce* prolactin. *Note: If this were a "multiple correct" style, Levodopa would also not cause hyperprolactinemia. However, Bromocriptine is the definitive pharmacological antagonist used for this purpose.* * **Chlordiazepoxide:** This is a benzodiazepine. Many psychotropic drugs (including certain benzodiazepines and especially antipsychotics) can cause hyperprolactinemia by interfering with central dopaminergic pathways. * **Pituitary Tumour:** A **Prolactinoma** is the most common secretory tumor of the pituitary gland and is a classic pathological cause of significantly elevated prolactin levels. **NEET-PG High-Yield Pearls:** * **Drug-Induced Hyperprolactinemia:** Most commonly caused by **Antipsychotics** (e.g., Risperidone, Haloperidol) and **Metoclopramide** due to D2-receptor blockade. * **Cabergoline:** Currently the drug of choice for prolactinomas due to its higher efficacy and longer half-life compared to Bromocriptine. * **Clinical Presentation:** In females, it presents as the **Amenorrhea-Galactorrhea syndrome**; in males, it causes decreased libido, erectile dysfunction, and gynecomastia.

Q: All of the following drugs alter calcium hemostasis except?

Indomethacin. ### Explanation The correct answer is **Indomethacin (Option B)**. **1. Why Indomethacin is the correct answer:** Indomethacin is a non-steroidal anti-inflammatory drug (NSAID) that acts primarily by inhibiting the enzyme cyclooxygenase (COX). While it is used clinically to treat hypercalcemia associated with certain malignancies (by inhibiting prostaglandin-mediated bone resorption), it does not directly alter physiological calcium homeostasis or serum calcium levels in a healthy individual. It lacks a direct mechanism of action on the parathyroid hormone (PTH), Vitamin D, or renal calcium handling. **2. Why the other options are incorrect:** * **Fluoride (Option A):** Fluoride is a potent stimulator of osteoblasts. In high doses (toxic levels), it can lead to hypocalcemia by causing rapid deposition of calcium into the bone (osteosclerosis) and can interfere with bone mineralization. * **Mithramycin (Plicamycin) (Option C):** This is a cytotoxic antibiotic that inhibits osteoclast activity. It is highly effective in lowering serum calcium levels and is specifically used in the emergency management of severe hypercalcemia of malignancy. * **Thiazides (Option D):** Thiazide diuretics (e.g., Hydrochlorothiazide) increase calcium reabsorption in the distal convoluted tubule of the kidney. This leads to **hypocalciuria** (decreased urine calcium) and can potentially cause mild **hypercalcemia**. **Clinical Pearls for NEET-PG:** * **Thiazides vs. Loop Diuretics:** Remember the mnemonic: *"Thiazides save calcium, Loops lose calcium."* Loop diuretics (Furosemide) are used to treat hypercalcemia because they promote calcium excretion. * **Mithramycin:** Though effective for hypercalcemia, its use is limited by significant toxicity (thrombocytopenia, hepatic, and renal toxicity). * **Bisphosphonates:** These are currently the first-line drugs for long-term management of hypercalcemia of malignancy.

Q: A patient is advised to take alendronate with a large amount of water and remain in the standing position for at least half an hour until the first meal of the day. These instructions are given to reduce the risk of:

Erosive esophagitis. **Explanation:** **1. Why Erosive Esophagitis is Correct:** Alendronate is a **bisphosphonate** used to treat osteoporosis. These drugs are highly acidic and can cause severe local irritation to the esophageal mucosa if they remain in contact with it for too long. If a tablet gets lodged or refluxes, it can lead to **erosive esophagitis**, esophageal ulcers, or even strictures. To prevent this, patients are instructed to: * Take the drug with a **full glass of water** (to ensure rapid transit to the stomach). * Maintain an **upright (standing or sitting) position** for at least 30 minutes (to prevent gastric reflux). * Remain **fasting** (to avoid interference with the drug's extremely low oral bioavailability, which is <1%). **2. Why Incorrect Options are Wrong:** * **A. Cholelithiasis:** Bisphosphonates do not affect bile composition or gallbladder motility; they are primarily excreted renally. * **B. Constipation:** While some oral medications cause GI upset, constipation is not a specific or dose-limiting side effect of alendronate. * **D. Osteonecrosis:** Specifically, **Osteonecrosis of the Jaw (ONJ)** is a known adverse effect of bisphosphonates, but it is typically associated with high-dose intravenous administration (e.g., in cancer patients) and dental trauma, not the immediate dosing posture or water intake. **3. NEET-PG High-Yield Pearls:** * **Mechanism of Action:** Bisphosphonates are pyrophosphate analogs that inhibit **osteoclasts** by interfering with the mevalonate pathway (specifically inhibiting farnesyl pyrophosphate synthase). * **Contraindication:** Alendronate is contraindicated in patients with esophageal abnormalities (e.g., achalasia) or those unable to stand/sit upright for 30 minutes. * **Alternative:** For patients with severe GI intolerance, intravenous **Zoledronate** (given once yearly) is an alternative.

Q: Which of the following is a side effect of Dapagliflozin?

All the above. **Explanation:** **Dapagliflozin** belongs to the **SGLT-2 (Sodium-Glucose Co-transporter 2) inhibitor** class of oral hypoglycemic agents. These drugs act on the proximal convoluted tubule of the kidney to inhibit glucose reabsorption, leading to **glycosuria** (excretion of glucose in the urine). **Why Option D is correct:** The mechanism of inducing glycosuria directly leads to the side effects mentioned: * **Increased Weight Loss:** Since glucose is excreted rather than stored or metabolized, there is a significant loss of calories (approx. 200–300 kcal/day), leading to weight reduction. * **Polyuria:** Glucose acts as an osmotic diuretic. Its presence in the renal tubule pulls water with it, increasing urine volume and frequency. * **Urinary Tract Infections (UTIs):** High glucose concentration in the urinary tract provides a fertile breeding ground for bacteria and fungi, leading to increased risks of UTIs and genital mycotic infections (candidiasis). **Why other options are considered:** Options A, B, and C are all documented side effects of SGLT-2 inhibitors. Therefore, "All the above" is the most comprehensive and accurate choice. **High-Yield Clinical Pearls for NEET-PG:** 1. **Euglycemic Ketoacidosis:** A rare but serious side effect where the patient has ketoacidosis despite relatively normal blood glucose levels. 2. **Cardio-Renal Protection:** SGLT-2 inhibitors are now preferred in patients with Heart Failure (reduced ejection fraction) and Chronic Kidney Disease (CKD) due to their protective effects. 3. **Fournier’s Gangrene:** A rare, life-threatening necrotizing fasciitis of the perineum associated with this drug class. 4. **Contraindication:** Generally not initiated if eGFR is <30 ml/min/1.73m².

Q: Magnesium is used in the treatment of which of the following conditions?

Tetany. **Explanation:** **Magnesium** acts as a physiological calcium channel blocker and plays a crucial role in neuromuscular stability. **1. Why Tetany is Correct:** Tetany is characterized by increased neuromuscular excitability. While most commonly associated with hypocalcemia, it can also be caused by **hypomagnesemia**. Magnesium is essential for the release of Parathyroid Hormone (PTH) and the responsiveness of end-organs to PTH. In cases of "refractory tetany" (where calcium levels are normal or calcium replacement fails), magnesium deficiency is the likely culprit. Administering Magnesium Sulfate ($MgSO_4$) restores ionic balance and stabilizes the neuronal membrane, effectively treating the tetany. **2. Why Other Options are Incorrect:** * **Diarrhea:** Magnesium salts (like Magnesium Citrate or Hydroxide) are **osmotic laxatives**. They cause diarrhea as a side effect or are used to treat constipation, not to treat diarrhea. * **Intractable Seizures:** While $MgSO_4$ is the drug of choice for **Eclamptic seizures**, it is not a first-line or standard treatment for general intractable seizures (Status Epilepticus), where Benzodiazepines, Phenytoin, or Levetiracetam are preferred. * **Cardiac Arrest:** Magnesium is not used in routine cardiac arrest. It is specifically indicated only if the arrest is caused by **Torsades de Pointes** (polymorphic ventricular tachycardia) or suspected hypomagnesemia. **Clinical Pearls for NEET-PG:** * **Drug of Choice:** $MgSO_4$ is the DOC for **Eclampsia** (prophylaxis and treatment) and **Torsades de Pointes**. * **Therapeutic Monitoring:** When administering $MgSO_4$, always monitor the **Patellar reflex** (first sign of toxicity is loss of reflex), respiratory rate, and urine output. * **Antidote:** The specific antidote for Magnesium toxicity is **Calcium Gluconate**.

Q: What is the standard dosage of Testosterone?

100 mg/week. **Explanation:** The standard replacement dose for testosterone in male hypogonadism aims to mimic the physiological production of testosterone in a healthy adult male, which is approximately **5–7 mg per day** (roughly 35–50 mg per week). **1. Why 100 mg/week is correct:** When using long-acting esters like **Testosterone Enanthate or Cypionate** (the most common injectable forms), the standard therapeutic dosage is **75–100 mg administered intramuscularly once a week**, or 200 mg every two weeks. This dosage typically maintains serum testosterone levels within the normal physiological range (300–1000 ng/dL) without causing excessive fluctuations or significant erythrocytosis. **2. Analysis of incorrect options:** * **150 mg/week & 200 mg/week:** While these doses are occasionally used in specific clinical scenarios, they often lead to supraphysiological peaks. Chronic administration at these levels increases the risk of side effects like polycythemia, acne, and gynecomastia (due to aromatization to estrogen). * **300 mg/week:** This is considered a **supraphysiological/performance-enhancing dose** rather than a medical replacement dose. It significantly increases the risk of cardiovascular strain and suppression of the HPT (Hypothalamic-Pituitary-Testicular) axis. **Clinical Pearls for NEET-PG:** * **Route of Administration:** Oral testosterone (undecanoate) has high first-pass metabolism; hence, injectable esters or transdermal patches/gels are preferred. * **Monitoring:** Always monitor **Hematocrit** (risk of polycythemia) and **PSA** (Prostate-Specific Antigen) before and during therapy. * **Contraindications:** Carcinoma of the prostate or breast in males is an absolute contraindication. * **Side Effects:** Cholestatic jaundice is specifically associated with **17-alpha-alkylated derivatives** (e.g., Methyltestosterone).

Question 1

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

Accepted Answer

Hypokalemia

Answer

Hypotensive state

Answer

Alcoholics

Answer

Renal failure

Question 2

Thiazolidinedione is associated with an increased risk of?

Accepted Answer

Heart failure

Answer

Pulmonary fibrosis

Answer

Myocarditis

Answer

Renal dysfunction

Question 3

Which of the following drugs or conditions does not cause hyperprolactinemia?

Accepted Answer

Bromocriptine

Answer

Levodopa

Answer

Chlordiazepoxide

Answer

Pituitary tumour

Question 4

Hypoglycemia may occur in a patient taking insulin and undergoing a surgical extraction when?

Accepted Answer

The extraction is performed on an empty stomach.

Answer

The patient has an active infection.

Answer

The patient has not exercised in the morning.

Answer

The patient consumed breakfast before the extraction.

Question 5

All of the following drugs alter calcium hemostasis except?

Accepted Answer

Indomethacin

Answer

Fluoride

Answer

Mithramycin

Answer

Thiazides

Question 6

Terlipressin is preferred over vasopressin for esophageal varices because of which reason?

Accepted Answer

Fewer side effects

Answer

Faster onset of action

Answer

Not metabolized

Answer

More potent

Question 7

A patient is advised to take alendronate with a large amount of water and remain in the standing position for at least half an hour until the first meal of the day. These instructions are given to reduce the risk of:

Accepted Answer

Erosive esophagitis

Answer

Cholelithiasis

Answer

Constipation

Answer

Osteonecrosis

Question 8

Which of the following is a side effect of Dapagliflozin?

Accepted Answer

All the above

Answer

Increased weight loss

Answer

Polyuria

Answer

Increased incidence of urinary tract infections

Question 9

Magnesium is used in the treatment of which of the following conditions?

Accepted Answer

Tetany

Answer

Diarrhea

Answer

Intractable seizures

Answer

Cardiac arrest

Question 10

What is the standard dosage of Testosterone?

Accepted Answer

100 mg/week

Answer

300 mg/week

Answer

200 mg/week

Answer

150 mg/week

Endocrine Pharmacology — MCQs

Endocrine Pharmacology — MCQs

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