A patient with pulmonary fibrosis comes to the emergency with arrhythmia. Which anti-arrhythmic drug should be avoided?
A 45 year old male, known case of Rheumatoid arthritis is on a monotherapy since many years. Symptoms of RA are controlled but suddenly patient develops blurring of vision. Which of the following drug is responsible for sudden effect on vision?
Anti-glaucoma drug that acts by increasing uveoscleral outflow is
A patient was on lithium therapy for bipolar disorder for 6 months. She fasted for few days due to religious reasons and presented with coarse tremors, abdominal pain, nausea, dizziness & confusion. Which of the following should be done to assess her condition?
What is the first-line drug for post-menopausal osteoporosis?
Which of the following is not a prokinetic?
NEET-PG 2020 - Pharmacology NEET-PG Practice Questions and MCQs
Question 21: A patient with pulmonary fibrosis comes to the emergency with arrhythmia. Which anti-arrhythmic drug should be avoided?
- A. Lignocaine
- B. Procainamide
- C. Verapamil
- D. Amiodarone (Correct Answer)
Explanation: ***Amiodarone*** - **Amiodarone** is known to cause **pulmonary toxicity** as a significant adverse effect, which can exacerbate pre-existing **pulmonary fibrosis**. - Its long half-life and **iodine content** contribute to its potential for delayed and severe pulmonary side effects, making it contraindicated in patients with existing lung disease. *Lignocaine* - **Lignocaine** (lidocaine) is a **Class IB antiarrhythmic** primarily used for **ventricular arrhythmias** and is generally safe in patients with pulmonary disease as it does not have significant pulmonary side effects. - Its main toxicities involve the **central nervous system** and cardiovascular system (at high doses). *Procainamide* - **Procainamide** is a **Class IA antiarrhythmic** that can be used for both **atrial and ventricular arrhythmias**, and it does not typically cause pulmonary toxicity. - Potential side effects include a **lupus-like syndrome**, agranulocytosis, and cardiotoxicity, none of which are exacerbated by pulmonary fibrosis. *Verapamil* - **Verapamil** is a **non-dihydropyridine calcium channel blocker** used for **supraventricular tachycardias** and rate control in atrial fibrillation, which does not have significant pulmonary side effects. - Its main concerns relate to **cardiac depression** and **hypotension**, but it is not contraindicated in the context of pulmonary fibrosis.
Question 22: A 45 year old male, known case of Rheumatoid arthritis is on a monotherapy since many years. Symptoms of RA are controlled but suddenly patient develops blurring of vision. Which of the following drug is responsible for sudden effect on vision?
- A. Methotrexate
- B. Hydroxychloroquine (Correct Answer)
- C. Sulfasalazine
- D. Leflunomide
Explanation: ***Hydroxychloroquine*** - **Hydroxychloroquine** [1] is known to cause **retinal toxicity** (maculopathy) as a dose-dependent, long-term side effect, leading to **blurring of vision** and other visual disturbances. - Patients on long-term hydroxychloroquine therapy require regular **ophthalmological screening** to detect and prevent irreversible vision loss. *Methotrexate* - **Methotrexate** is a common DMARD used in RA [1], but its ocular side effects are typically rare and less severe, usually involving **conjunctivitis** or **periorbital edema**. - It does not commonly cause **maculopathy** or sudden profound blurring of vision. *Sulfasalazine* - **Sulfasalazine** [1] can cause a range of side effects, including gastrointestinal issues and various hypersensitivity reactions. - Ocular side effects are infrequent and generally mild, such as **conjunctivitis** or **periorbital edema**, and not severe blurring of vision due to retinal damage. *Leflunomide* - **Leflunomide** is an immunosuppressive DMARD [1] whose common adverse effects include hepatotoxicity, gastrointestinal upset, and hypertension. - Significant **ocular toxicity** leading to blurring of vision, particularly retinal damage, is not a characteristic side effect of **leflunomide**.
Question 23: Anti-glaucoma drug that acts by increasing uveoscleral outflow is
- A. Dorzolamide
- B. Latanoprost (Correct Answer)
- C. Pilocarpine
- D. Timolol
Explanation: ***Latanoprost*** - **Latanoprost** is a **prostaglandin F2α analog** that effectively lowers intraocular pressure by significantly increasing **uveoscleral outflow**. - It works by remodeling the extracellular matrix in the ciliary body and sclera, which facilitates the drainage of aqueous humor through the uveoscleral pathway. *Dorzolamide* - **Dorzolamide** is a **topical carbonic anhydrase inhibitor** that reduces the production of aqueous humor, thus lowering intraocular pressure. - It does not directly affect the uveoscleral outflow pathway. *Pilocarpine* - **Pilocarpine** is a **cholinergic agonist** that primarily works by increasing the **trabecular outflow** of aqueous humor through contraction of the ciliary muscle [1]. - It does not significantly influence the uveoscleral outflow pathway. *Timolol* - **Timolol** is a **beta-adrenergic blocker** that reduces aqueous humor production by the ciliary body [1]. - Its mechanism of action involves decreasing the formation, rather than increasing the outflow, of aqueous humor [1].
Question 24: A patient was on lithium therapy for bipolar disorder for 6 months. She fasted for few days due to religious reasons and presented with coarse tremors, abdominal pain, nausea, dizziness & confusion. Which of the following should be done to assess her condition?
- A. ECG
- B. S. lithium levels (Correct Answer)
- C. MRI
- D. S. electrolytes
Explanation: ***S. lithium levels*** - The patient's symptoms (coarse tremors, abdominal pain, nausea, dizziness, confusion) are classic for **lithium toxicity**, which is exacerbated by **dehydration** from fasting [1], [2]. - Measuring **serum lithium levels** is crucial for confirming the diagnosis and guiding immediate management [1]. *ECG* - While lithium toxicity can cause **cardiac arrhythmias** (QT prolongation, T-wave changes), an ECG is a secondary assessment to evaluate for complications, not the primary diagnostic test for toxicity itself. - An ECG doesn't directly measure lithium concentration, which is essential for diagnosing toxicity. *S. electrolyte* - **Electrolyte imbalances**, particularly **hyponatremia**, can worsen lithium toxicity by affecting its renal excretion [2]. - While important to check for contributing factors and guide supportive care, measuring electrolytes is secondary to confirming elevated lithium levels as the cause of symptoms. *MRI* - An **MRI of the brain** is not indicated for the initial assessment of suspected lithium toxicity. - It would only be considered if there were concerns for focal neurological deficits or other structural brain abnormalities, which are not directly suggested by the presented symptoms of lithium toxicity.
Question 25: What is the first-line drug for post-menopausal osteoporosis?
- A. Raloxifene
- B. Calcitonin
- C. Bisphosphonates (Correct Answer)
- D. Oestrogen
Explanation: **Bisphosphonates** - **Bisphosphonates** are the **first-line therapy** for postmenopausal osteoporosis due to their proven efficacy in reducing the risk of fragility fractures. - They work by **inhibiting osteoclast activity**, thereby reducing bone resorption and increasing bone mineral density. *Raloxifene* - **Raloxifene** is a **selective estrogen receptor modulator (SERM)** that can be used for osteoporosis prevention and treatment, but it is typically a second-line option, especially in women who cannot tolerate bisphosphonates or have an increased risk of breast cancer. - While it has a positive effect on bone density, its fracture-reduction efficacy is not as broad as bisphosphonates (e.g., it reduces vertebral fractures but has less consistent data on non-vertebral fractures). *Calcitonin* - **Calcitonin** is generally reserved for patients who cannot tolerate other therapies or for short-term use in acute vertebral fractures to help with pain relief. - Its efficacy in reducing fracture risk is **less robust** compared to bisphosphonates, and it is not considered a first-line agent. *Oestrogen* - **Estrogen (hormone replacement therapy)** was once a primary treatment but is now generally not recommended as first-line for osteoporosis due to concerns about increased risks of breast cancer, cardiovascular events, and stroke, particularly in older women. - It is typically reserved for women with significant menopausal symptoms for whom other therapies are contraindicated or ineffective, and for the shortest duration possible.
Question 26: Which of the following is not a prokinetic?
- A. Macrolides
- B. D2 blocker
- C. 5HT4 agonist
- D. Loperamide derivative (Correct Answer)
Explanation: **Loperamide derivative** - **Loperamide** is an **opioid receptor agonist** that acts on the mu-opioid receptors in the gut, primarily to **decrease gastrointestinal motility** and treat diarrhea. - Its mechanism of action directly opposes that of prokinetic agents, which aim to increase GI motility. *Macrolides* - Certain macrolide antibiotics, particularly **erythromycin**, act as **motilin receptor agonists** at low doses. - This agonism leads to increased gastric motility and can be used as a prokinetic in conditions like gastroparesis. *D2 blocker* - **Dopamine D2 receptor antagonists** (e.g., **metoclopramide**, **domperidone**) block the inhibitory effect of dopamine on cholinergic smooth muscle. - This blockade enhances acetylcholine release, leading to increased gastrointestinal motility and prokinetic effects. *5HT4 agonist* - **Serotonin 5-HT4 receptor agonists** (e.g., **cisapride**, **prucalopride**) stimulate the release of acetylcholine and other excitatory neurotransmitters in the enteric nervous system. - This action promotes increased gastrointestinal motility, making them effective prokinetic agents.