NEET-PG 2012 - Pharmacology Practice Questions

Q: Which of the following statements about dopamine is false?

Causes increase in GI Ischemia. ***Causes increase in GI Ischemia*** (FALSE Statement) - This statement is **incorrect and misleading** as dopamine does not primarily "cause increase in GI ischemia" - While dopamine at **higher doses** can cause **splanchnic vasoconstriction** via alpha-1 receptors, this is not characterized as "causing GI ischemia" in standard pharmacology - GI ischemia is a potential adverse effect in susceptible patients, but not a primary pharmacological effect or standard clinical description of dopamine *Positive inotropic* (TRUE Statement) - Dopamine is a **catecholamine** with dose-dependent effects; at **moderate doses (5-10 mcg/kg/min)**, it stimulates **beta-1 adrenergic receptors** in the heart - This beta-1 stimulation leads to increased **myocardial contractility** and **heart rate**, thus exerting a **positive inotropic effect** - This is a well-established therapeutic effect of dopamine *Improves renal perfusion* (TRUE Statement) - At **low doses (0.5-3 mcg/kg/min)**, dopamine selectively activates **dopamine-1 (D1) receptors** in the renal vasculature - This activation causes **renal vasodilation**, leading to increased **renal blood flow**, improved **glomerular filtration rate**, and enhanced **sodium excretion** - This "renal dose" effect is a classic pharmacological property of dopamine *Causes Vasoconstriction* (TRUE Statement) - At **high doses (>10 mcg/kg/min)**, dopamine primarily stimulates **alpha-1 adrenergic receptors** - This leads to generalized **vasoconstriction**, increasing **systemic vascular resistance** and **blood pressure** - This dose-dependent alpha effect is well-documented

Q: As per RNTCP guidelines, Multi drug resistance (MDR) TB is defined as resistance to:

Rifampicin and isoniazid. ***Rifampicin and isoniazid*** - According to **RNTCP guidelines** (now NTEP), **MDR-TB** is specifically defined as tuberculosis that is resistant to at least both **rifampicin** and **isoniazid**. - These two drugs are the **most potent first-line anti-TB medications**, and resistance to both significantly complicates treatment. *Rifampicin* - While resistance to **rifampicin alone** is a serious concern, it is classified as **rifampicin-resistant TB (RR-TB)**, not full **MDR-TB**. - **MDR-TB** requires resistance to at least two key first-line drugs. *Rifampicin, isoniazid and ethambutol* - Resistance to **rifampicin**, **isoniazid**, and **ethambutol** would be a form of **MDR-TB** (as it includes resistance to rifampicin and isoniazid), but it is a more extensive form of resistance. - The minimum definition of **MDR-TB** focuses on the two most crucial first-line drugs. *None of the above* - This option is incorrect because there is a specific definition for **MDR-TB** that aligns with one of the provided choices. - The guidelines clearly define **MDR-TB** based on resistance to specific drugs.

Q: All are true about ciprofloxacin except?

More active at acidic pH. ***More active at acidic pH*** - Fluoroquinolones, including ciprofloxacin, exhibit **reduced antibacterial activity in acidic environments**. Their efficacy is generally better at **neutral or alkaline pH**. - This is clinically relevant as fluoroquinolones may have **reduced effectiveness in acidic sites** like the stomach or acidic urine. - The optimal antibacterial activity occurs at physiological or slightly alkaline pH. *DNA gyrase inhibition* - Ciprofloxacin, like other fluoroquinolones, exerts its antibacterial effect by inhibiting **bacterial DNA gyrase (topoisomerase II)** and **topoisomerase IV**. - This inhibition prevents DNA replication and repair, leading to bacterial cell death. *Contraindicated in pregnancy* - Ciprofloxacin is generally **contraindicated in pregnancy** due to concerns about potential harm to the developing fetus, particularly effects on **cartilage development**. - However, it may be used in specific, life-threatening situations if the benefit outweighs the potential risk. *Second generation fluoroquinolone* - Ciprofloxacin is classified as a **second-generation fluoroquinolone**. - This class includes agents with improved activity against Gram-negative bacteria and some atypical organisms.

Q: Which of the following is not a selective serotonin reuptake inhibitor?

Buspirone. ***Buspirone*** - **Buspirone** is an anxiolytic that primarily acts as a **serotonin 5-HT1A receptor partial agonist**, not an SSRI. - It does not significantly affect the reuptake of serotonin, distinguishing it from SSRIs. *Fluoxetine* - **Fluoxetine** is a well-known and widely used **SSRI**. - It works by selectively inhibiting the reuptake of serotonin, thereby increasing its concentration in the synaptic cleft. *Fluvoxamine* - **Fluvoxamine** is another antidepressant classified as an **SSRI**. - It is often used for the treatment of **obsessive-compulsive disorder (OCD)** due to its strong serotonin reuptake inhibition. *Citalopram* - **Citalopram** is an **SSRI** frequently prescribed for depression and anxiety disorders. - Its mechanism involves potent and selective inhibition of **serotonin reuptake**.

Q: Which of the following is NOT caused by Prostaglandin E2 (PGE2)?

None of the options. ***None of the options*** - All three listed effects (water retention, uterine contraction, and flushing) **ARE caused by Prostaglandin E2 (PGE2)**, making this the correct answer to the question asking what is NOT caused by PGE2. - Since PGE2 actually causes all the listed effects, "None of the options" is the accurate response. *Water retention* - PGE2 **stimulates ADH (vasopressin) release** from the posterior pituitary gland. - PGE2 also **enhances ADH action** on renal collecting ducts, promoting water reabsorption. - While PGE2 has complex renal effects including natriuresis, its net effect includes **promoting water retention** through the ADH mechanism. - This is an important effect of PGE2 on fluid balance. *Uterine contraction* - PGE2 is a **potent stimulator of uterine smooth muscle contraction**. - It is used clinically for **labor induction** and **cervical ripening** (dinoprostone). - PGE2 plays a crucial role in **parturition** and is involved in **dysmenorrhea**. *Flushing* - PGE2 causes **peripheral vasodilation**, particularly in cutaneous blood vessels. - This vasodilatory effect leads to **increased skin blood flow**, manifesting as **flushing** and warmth. - This is commonly seen as part of the **inflammatory response** and contributes to erythema.

Q: What is the primary therapeutic use of 5-HT1B/1D agonists?

Acute migraine treatment. ***Acute migraine treatment*** - 5-HT1B/1D agonists, such as **triptans**, primarily work by causing **vasoconstriction of intracranial blood vessels** and inhibiting the release of pro-inflammatory neuropeptides. - This action directly alleviates the pain and associated symptoms of **acute migraine attacks**. *Anti-anxiety medications* - Anti-anxiety medications typically target neurotransmitter systems like **GABA** (e.g., benzodiazepines) or **serotonin reuptake** (e.g., SSRIs), not the 5-HT1B/1D receptors in this context. - While serotonin plays a role in anxiety, specific 5-HT1B/1D agonism does not lead to anxiolytic effects. *Anti-nausea medications for chemotherapy* - Anti-nausea medications used for chemotherapy-induced nausea and vomiting often target **5-HT3 receptors** (e.g., ondansetron) to block their pro-emetic effects. - 5-HT1B/1D agonists do not have primary anti-emetic properties useful in this setting. *Drugs for gastroesophageal reflux disease (GERD)* - GERD medications primarily focus on reducing stomach acid production (e.g., **proton pump inhibitors**, H2 blockers) or neutralizing it (antacids). - 5-HT1B/1D agonists do not directly influence gastric acid secretion or esophageal motility in a way beneficial for GERD.

Q: Which medication increases the efficacy of salmeterol when used together?

Corticosteroid. ***Corticosteroid*** - **Corticosteroids** act synergistically with **beta-2 agonists** like salmeterol by increasing the number and sensitivity of beta-2 receptors on bronchial smooth muscle cells. - They also reduce inflammation, which contributes to airway hyperresponsiveness, thereby improving the overall efficacy of bronchodilators. *Theophylline* - **Theophylline** is a methylxanthine that causes bronchodilation through inhibition of phosphodiesterase, but it is not directly synergistic with **salmeterol** in potentiating its primary action. - While both treat airway obstruction, their mechanisms are distinct, and theophylline has a narrow therapeutic index with significant side effects. *Ipratropium* - **Ipratropium** is an **anticholinergic bronchodilator** that blocks muscarinic receptors, leading to bronchodilation. - Its mechanism of action is different from that of **salmeterol (a beta-2 agonist)**, and while they can be used together for additive bronchodilation, ipratropium does not directly increase the efficacy of salmeterol itself. *Sodium cromoglycate* - **Sodium cromoglycate** is a **mast cell stabilizer** that prevents the release of inflammatory mediators, primarily used for asthma prophylaxis. - It does not have direct bronchodilatory effects and does not enhance the bronchodilatory action of **salmeterol**.

Q: Which of the following is a centrally acting antihypertensive drug?

Methyldopa. ***Methyldopa*** - **Methyldopa** is a **prodrug** that is converted to **alpha-methylnorepinephrine** in the brain, which then stimulates **alpha-2 adrenergic receptors** in the brainstem. - This stimulation reduces **sympathetic outflow** from the central nervous system, leading to decreased heart rate, stroke volume, and peripheral vascular resistance, thus lowering blood pressure. *Phenoxybenzamine* - **Phenoxybenzamine** is an **alpha-1 and alpha-2 adrenergic receptor antagonist** (non-selective alpha blocker) that primarily acts peripherally. - It causes **vasodilation** by blocking alpha-1 receptors on smooth muscle, which reduces peripheral vascular resistance. *Propranolol* - **Propranolol** is a **non-selective beta-blocker** that primarily acts on peripheral beta-adrenergic receptors. - It reduces heart rate and cardiac output by blocking **beta-1 receptors** in the heart and can also affect beta-2 receptors in the lungs and vasculature. *Prazosin* - **Prazosin** is a **selective alpha-1 adrenergic receptor antagonist** that acts primarily on peripheral blood vessels. - It causes **vasodilation** in both arteries and veins by blocking alpha-1 receptors, which reduces both preload and afterload, lowering blood pressure.

Q: Which of the following antineoplastic drugs SHOULD NOT be given by rapid IV infusion?

Cisplatin. ***Cisplatin*** - **Cisplatin** is highly nephrotoxic and emetogenic; rapid IV infusion can exacerbate these adverse effects, leading to severe renal damage and intractable nausea/vomiting. - It typically requires **prolonged infusion times** (e.g., 6-8 hours) with extensive pre- and post-hydration to reduce kidney toxicity and ensure patient tolerance. *Cyclophosphamide* - While cyclophosphamide can cause **hemorrhagic cystitis**, this is managed by adequate hydration and mesna, and its infusion rate is generally not as critically prolonged as cisplatin's. - It is often administered as a **relatively quick IV infusion** over 30-60 minutes, emphasizing hydration. *Bleomycin* - **Bleomycin** is known for pulmonary toxicity and hypersensitivity reactions, but these are not primarily linked to its infusion rate. - It is commonly given via **slow IV push or short infusion**, sometimes with a test dose to assess for hypersensitivity. *Cytosine arabinoside* - **Cytosine arabinoside** can cause myelosuppression and cerebellar toxicity, but these toxicities are not typically exacerbated by a rapid infusion rate. - It is often administered via a **continuous infusion** over several days or as a rapid IV bolus.

Q: What is Dinoprost?

Prostaglandin F2α (PGF2α). ***Prostaglandin F2α (PGF2α)*** - **Dinoprost** is the generic name for **Prostaglandin F2α**. - It works by stimulating **myometrial contractions** and promoting cervical ripening, making it useful in obstetrics. *Prostaglandin E2 (PGE2)* - **PGE2** is known as **Dinoprostone** and is also used for cervical ripening and labor induction. - While similar in function, **Dinoprostone** (PGE2) is distinct from **Dinoprost** (PGF2α). *Prostaglandin I2 (PGI2)* - **PGI2** is also known as **Prostacyclin** and acts as a potent **vasodilator** and **inhibitor of platelet aggregation**. - Its primary therapeutic uses are in conditions like **pulmonary hypertension**, which differs from Dinoprost's obstetric uses. *Prostaglandin E1 (PGE1)* - **PGE1** is also known as **Alprostadil** and is used to maintain the **patency of the ductus arteriosus** in neonates with certain congenital heart defects. - It is distinct from Dinoprost and has different clinical applications.

Question 1

Which of the following statements about dopamine is false?

Accepted Answer

Causes increase in GI Ischemia

Answer

Improves renal perfusion

Answer

Causes Vasoconstriction

Answer

Positive ionotropic

Question 2

As per RNTCP guidelines, Multi drug resistance (MDR) TB is defined as resistance to:

Accepted Answer

Rifampicin and isoniazid

Answer

Rifampicin

Answer

Rifampicin, isoniazid and ethambutol

Answer

None of the above

Question 3

All are true about ciprofloxacin except?

Accepted Answer

More active at acidic pH

Answer

DNA gyrase inhibition

Answer

Contraindicated in pregnancy

Answer

Second generation fluoroquinolone

Question 4

Which of the following is not a selective serotonin reuptake inhibitor?

Accepted Answer

Buspirone

Answer

Citalopram

Answer

Fluoxetine

Answer

Fluvoxamine

Question 5

Which of the following is NOT caused by Prostaglandin E2 (PGE2)?

Accepted Answer

None of the options

Answer

Water retention

Answer

Flushing

Answer

Uterine contraction

Question 6

What is the primary therapeutic use of 5-HT1B/1D agonists?

Accepted Answer

Acute migraine treatment

Answer

Anti-anxiety medications

Answer

Anti-nausea medications for chemotherapy

Answer

Drugs for gastroesophageal reflux disease (GERD)

Question 7

Which medication increases the efficacy of salmeterol when used together?

Accepted Answer

Corticosteroid

Answer

Theophylline

Answer

Ipratropium

Answer

Sodium cromoglycate

Question 8

Which of the following is a centrally acting antihypertensive drug?

Accepted Answer

Methyldopa

Answer

Phenoxybenzamine

Answer

Propranolol

Answer

Prazosin

Question 9

Which of the following antineoplastic drugs SHOULD NOT be given by rapid IV infusion?

Accepted Answer

Cisplatin

Answer

Cyclophosphamide

Answer

Cytosine arabinoside

Answer

Bleomycin

Question 10

What is Dinoprost?

Accepted Answer

Prostaglandin F2α (PGF2α)

Answer

Prostaglandin E2 (PGE2)

Answer

Prostaglandin I2 (PGI2)

Answer

Prostaglandin E1 (PGE1)

NEET-PG 2012 — Pharmacology