NEET-PG 2020 - Pharmacology Practice Questions

Q: A boy is planning to travel by bus. Which of the following drugs can be used to prevent motion sickness in this person?

Promethazine. **Promethazine** - **Promethazine** is an **H1 antihistamine** with significant **anticholinergic** properties that effectively blocks muscarinic receptors in the **vestibular system**, making it highly effective for preventing motion sickness. - Its **sedating effects** are also beneficial in relieving the discomfort associated with motion sickness. *Fexofenadine* - **Fexofenadine** is a **second-generation H1 antihistamine** that is **non-sedating** and has minimal anticholinergic activity. - While effective for allergies, its lack of central nervous system penetration and anticholinergic action makes it **ineffective for motion sickness**. *Loratadine* - **Loratadine** is another **second-generation H1 antihistamine**, known for being **non-sedating** and having limited entry into the central nervous system. - It does not possess the significant anticholinergic properties necessary to prevent the **vestibular disturbances** that cause motion sickness. *Cetirizine* - **Cetirizine** is a **second-generation H1 antihistamine** that has **moderate sedative effects** (more than other second-generation agents) and some CNS penetration, but lacks the significant **anticholinergic activity** required for motion sickness prevention. - It is primarily used for allergies and is **not recommended** for the prevention or treatment of motion sickness.

Q: A patient with pulmonary fibrosis comes to the emergency with arrhythmia. Which anti-arrhythmic drug should be avoided?

Amiodarone. ***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.

Q: 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?

Hydroxychloroquine. ***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**.

Q: Anti-glaucoma drug that acts by increasing uveoscleral outflow is

Latanoprost. ***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].

Q: What is the first-line drug for post-menopausal osteoporosis?

Bisphosphonates. **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.

Q: Which of the following is not a prokinetic?

Loperamide derivative. **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.

Q: Which of the following drugs shown in the graph below has highest potency?

Drug A. ***Drug A*** - **Potency** is determined by the concentration (or dose) of a drug required to produce 50% of its maximal effect (**EC50** or **ED50**). On a dose-response curve, the drug shifted furthest to the **left** (requiring a lower dose) is the most potent. - Drug A reaches 50% of its maximum effect at the **lowest concentration** compared to Drugs B and C, indicating higher potency. *Drug B* - Drug B requires a **higher concentration** than Drug A to achieve 50% of its maximal effect, indicating it is less potent than Drug A. - While Drug B reaches the same maximal effect as Drug A, its dose-response curve is shifted to the **right** of Drug A's. *Both Drug A and Drug B* - Although both drugs reach the same **maximal efficacy**, their potencies differ significantly. - Drug A achieves this maximal effect at a much **lower dose** than Drug B. *Drug C* - Drug C not only requires a **higher concentration** to reach its maximal effect but also exhibits a **lower maximal efficacy** compared to Drugs A and B. - Both its potency and efficacy are **lower** than those of Drug A.

Question 1

A boy is planning to travel by bus. Which of the following drugs can be used to prevent motion sickness in this person?

Accepted Answer

Promethazine

Answer

Fexofenadine

Answer

Loratadine

Answer

Cetirizine

Question 2

A patient with pulmonary fibrosis comes to the emergency with arrhythmia. Which anti-arrhythmic drug should be avoided?

Accepted Answer

Amiodarone

Answer

Lignocaine

Answer

Procainamide

Answer

Verapamil

Question 3

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?

Accepted Answer

Hydroxychloroquine

Answer

Methotrexate

Answer

Sulfasalazine

Answer

Leflunomide

Question 4

Anti-glaucoma drug that acts by increasing uveoscleral outflow is

Accepted Answer

Latanoprost

Answer

Dorzolamide

Answer

Pilocarpine

Answer

Timolol

Question 5

What is the first-line drug for post-menopausal osteoporosis?

Accepted Answer

Bisphosphonates

Answer

Raloxifene

Answer

Calcitonin

Answer

Oestrogen

Question 6

Which of the following is not a prokinetic?

Accepted Answer

Loperamide derivative

Answer

Macrolides

Answer

D2 blocker

Answer

5HT4 agonist

Question 7

Which of the following drugs shown in the graph below has highest potency?

Accepted Answer

Drug A

Answer

Drug B

Answer

Both Drug A and Drug B

Answer

Drug C

NEET-PG 2020 — Pharmacology