NEET-PG 2013 Practice Questions

Q: What is the drug of choice for bleeding oesophageal varices?

Octreotide. ***Octreotide*** - **Octreotide** is an analogue of **somatostatin** that reduces splanchnic blood flow and portal pressure, thereby decreasing bleeding from esophageal varices. - It is often used in the acute management of **bleeding esophageal varices** due to its rapid onset of action and favorable safety profile. *Ethanolamine oleate* - **Ethanolamine oleate** is a **sclerosing agent** used for endoscopic sclerotherapy of esophageal varices, not typically as the initial drug of choice for acute bleeding [1]. - It acts by causing inflammation and fibrosis of the varices, which can be effective but carries risks such as **esophageal ulceration** or perforation. *Propranolol* - **Propranolol** is a **non-selective beta-blocker** used for the prophylactic prevention of variceal bleeding, not for acute management of active bleeding. - It works by reducing portal venous pressure by decreasing cardiac output and splanchnic vasoconstriction. *Phytonadione* - **Phytonadione** (vitamin K1) is used to reverse **coumarin anticoagulant effects** or to treat **vitamin K deficiency**, which can contribute to bleeding but is not a direct treatment for variceal bleeding itself. - It helps in the synthesis of **coagulation factors II, VII, IX, and X**, thereby improving clotting.

Q: Cytolytic activity of membrane attack complex is modulated by ?

Factor S (vitronectin). ***Correct Option: Factor S (vitronectin)*** - Vitronectin (S-protein) is a **plasma protein** that directly modulates the **cytolytic activity of the membrane attack complex (MAC)**. - It binds to the **C5b-7 complex** in the fluid phase, preventing its insertion into target cell membranes and thereby blocking the formation of the complete, functional MAC. - By inhibiting membrane insertion of C5b-7, vitronectin prevents the subsequent binding of **C8 and C9**, which are essential for the cytolytic pore formation. - This is a **direct modulation** of MAC's cytolytic activity at the MAC assembly stage. *Incorrect Option: Factor H* - Factor H is a regulatory protein that controls the **alternative pathway** of complement activation by promoting degradation of **C3b**. - By degrading C3b, Factor H prevents formation of **C5 convertase**, thereby reducing downstream MAC formation. - However, Factor H acts **early in the complement cascade** and does not directly modulate the cytolytic activity of already-formed MAC components. - Its effect is on **preventing MAC formation**, not on modulating MAC's cytolytic function itself. *Incorrect Option: Factor I* - Factor I is a **serine protease** that cleaves and inactivates C3b and C4b, requiring cofactors like Factor H or C4bp. - Like Factor H, it regulates complement activation **upstream** of MAC formation. - It does not directly interact with or modulate the cytolytic activity of the MAC. *Incorrect Option: Factor B* - Factor B is a component of the **alternative pathway C3 convertase** (C3bBb). - It **promotes complement activation** rather than modulating MAC's cytolytic activity. - Factor B functions early in the cascade and has no direct role in regulating MAC function.

Q: Which among the following is an absolute contraindication of Hormone replacement therapy?

Breast carcinoma. ### Breast carcinoma - Hormone replacement therapy (HRT) is **contraindicated** in breast carcinoma because many breast cancers are **estrogen-receptor positive**, meaning estrogen can stimulate their growth [1]. - Using HRT in patients with a history of breast cancer significantly increases the risk of **recurrence** or **progression** of the disease [1]. *Endometriosis* - Endometriosis is not an **absolute contraindication**; HRT can sometimes be used in women with a history of endometriosis, especially if a hysterectomy and bilateral oophorectomy have been performed. - However, unopposed estrogen therapy might **exacerbate** remaining endometrial implants, so a combined estrogen-progestin regimen is typically preferred [1]. *Heart disease* - While HRT has been shown to have **risks** in women with established coronary heart disease, it is not an absolute contraindication for all forms of heart disease. - The **Women's Health Initiative study** demonstrated increased cardiovascular events in older women initiating HRT, but current guidelines suggest that timing of initiation is crucial and benefits may outweigh risks for younger postmenopausal women. *Osteoarthritis* - Osteoarthritis is **not a contraindication** to HRT; in fact, some studies suggest that estrogen may have protective effects on cartilage [2]. - HRT is neither a treatment nor a contraindication for osteoarthritis and does not significantly impact its progression or severity [2].

Q: Which of the following is the longest acting glucocorticoid?

Dexamethasone. ***Correct: Dexamethasone*** - **Dexamethasone** is a long-acting glucocorticoid with a **biological half-life of 36–72 hours**, making it the longest acting among the options provided - Its prolonged action is due to its **high affinity for the glucocorticoid receptor** and relatively slow metabolism - Provides sustained anti-inflammatory and immunosuppressive effects *Incorrect: Prednisone* - **Prednisone** is an intermediate-acting glucocorticoid with a biological half-life of 12-36 hours - Requires metabolism in the liver to its active form, prednisolone - Duration of action is significantly shorter than dexamethasone *Incorrect: Prednisolone* - **Prednisolone** is the active form of prednisone, with a similar intermediate duration of action (12-36 hours) - Primarily used when liver conversion of prednisone is impaired - Does not possess the extended duration of action characteristic of dexamethasone *Incorrect: Cortisone* - **Cortisone** is a short-acting glucocorticoid with a biological half-life of 8-12 hours - It is a prodrug that needs to be converted to **hydrocortisone** (cortisol) in the liver to become active - Has the shortest duration among all options

Q: Which of the following is the most potent topical corticosteroid?

Clobetasol propionate. ***Clobetasol propionate*** - **Clobetasol propionate** is recognized as one of the most potent **Class I topical corticosteroids**, used for severe inflammatory skin conditions. - Its high potency allows for effective suppression of severe inflammation and pruritus, but also carries a greater risk of **adverse effects** with prolonged use. *Triamcinolone acetonide* - **Triamcinolone acetonide** is a **medium-potency** topical corticosteroid (Class IV-V), less potent than clobetasol propionate. - It is commonly used for moderate inflammatory skin conditions, such as eczema and psoriasis, but not for severe cases requiring maximum potency. *Hydrocortisone acetate* - **Hydrocortisone acetate** is a **low-potency** topical corticosteroid (Class VII), making it the least potent option listed. - It's often used for mild inflammatory conditions, sensitive areas like the face, or for less severe conditions requiring minimal corticosteroid strength. *Betamethasone valerate* - **Betamethasone valerate** is a **medium-to-high potency** topical corticosteroid (Class III-V), placing it among stronger corticosteroids but still less potent than clobetasol propionate. - It is effective for moderate to severe inflammatory skin conditions but does not reach the highest level of potency demonstrated by clobetasol.

Q: Which of the following reduces the efficacy of oral contraceptives?

Griseofulvin. ***Griseofulvin*** - **Griseofulvin** is an antifungal agent known to induce liver enzymes, specifically the **cytochrome P450 system**. - Enzyme induction accelerates the metabolism and clearance of **oral contraceptives**, leading to lower plasma concentrations and reduced efficacy. *Erythromycin* - **Erythromycin** is a macrolide antibiotic that typically inhibits liver enzymes rather than inducing them. - While it can interfere with the metabolism of some drugs, it usually **increases** rather than decreases the plasma levels of co-administered medications, and is not known to reduce oral contraceptive efficacy. *Disulfiram* - **Disulfiram** is used to treat chronic alcoholism and inhibits aldehyde dehydrogenase. - It does not significantly interact with the metabolism of **oral contraceptives** via the cytochrome P450 system or other mechanisms that would reduce their efficacy. *Cimetidine* - **Cimetidine** is an H2 receptor antagonist that is known to inhibit cytochrome P450 enzymes. - This inhibition would likely **increase** the plasma concentration of drugs metabolized by these enzymes, such as oral contraceptives, rather than reducing their efficacy.

Q: Which of the following is a tricyclic antidepressant?

Doxepin. ***Doxepin*** - **Doxepin** is a **tricyclic antidepressant (TCA)** that inhibits the reuptake of **serotonin** and **norepinephrine**, and also has significant **histaminergic** and **cholinergic** blocking effects. - TCAs, including doxepin, are commonly used for treating **depression**, **anxiety**, and certain pain conditions. *Venlafaxine* - **Venlafaxine** is a **serotonin-norepinephrine reuptake inhibitor (SNRI)**, not a tricyclic antidepressant. - SNRIs selectively block the reuptake of both **serotonin** and **norepinephrine**, but lack the broad receptor affinity of TCAs. *Fluoxetine* - **Fluoxetine** is a **selective serotonin reuptake inhibitor (SSRI)**, which specifically targets serotonin reuptake. - SSRIs are generally considered a first-line treatment for depression due to a more favorable side effect profile compared to TCAs. *Citalopram* - **Citalopram** is also a **selective serotonin reuptake inhibitor (SSRI)**, much like fluoxetine. - It works by increasing the levels of **serotonin** in the brain by blocking its reuptake, differentiating it from tricyclic antidepressants.

Q: Which of the following is a classic tricyclic antidepressant (TCA) commonly used as the prototype for the class?

Amitriptyline. ***Amitriptyline*** - **Amitriptyline** is a classic tricyclic antidepressant (TCA) and is widely recognized for its use in treating depression, neuropathic pain, and migraine prophylaxis. Its characteristic side effect profile, including **anticholinergic effects** and **sedation**, is well-known. - It is one of the **oldest and most frequently prescribed TCAs**, making it a common reference point in pharmacology and clinical practice. *Citalopram* - **Citalopram** is an **SSRI** (selective serotonin reuptake inhibitor), not a TCA. It works by selectively inhibiting the reuptake of serotonin. - It has a different side effect profile compared to TCAs, generally with fewer anticholinergic and cardiovascular effects. *Venlafaxine* - **Venlafaxine** is an **SNRI** (serotonin-norepinephrine reuptake inhibitor), not a TCA. It inhibits the reuptake of both serotonin and norepinephrine. - It has efficacy in treating depression and anxiety disorders, but its mechanism of action is distinct from TCAs. *Nortriptyline* - **Nortriptyline** is indeed a TCA, specifically a **secondary amine TCA**, which is an active metabolite of amitriptyline. - While it is a TCA, amitriptyline is generally more broadly recognized and used as the prototype for the class, with nortriptyline often being highlighted for its slightly better tolerability profile (e.g., less sedation, less orthostatic hypotension) compared to tertiary amine TCAs like amitriptyline.

Q: Mechanism of action of tranexamic acid is

Prevents fibrinolysis. ***Correct: Prevents fibrinolysis*** - Tranexamic acid is an **antifibrinolytic agent** that works by inhibiting the activation of plasminogen to plasmin. - By preventing the formation of plasmin, it stabilizes **fibrin clots** and reduces bleeding. *Incorrect: Decrease vascular permeability* - This is primarily the mechanism of action of drugs like antihistamines or corticosteroids, which work on **inflammation** and **allergic reactions**. - Tranexamic acid does not directly target vascular permeability; its primary role is in **hemostasis**. *Incorrect: Smooth muscle contraction* - This describes the action of drugs like **vasoconstrictors** (e.g., epinephrine) or agents that promote uterine contractions (e.g., oxytocin). - Tranexamic acid has no direct effect on **smooth muscle contraction**. *Incorrect: Activates Plasmin formation* - This is the opposite of tranexamic acid's action; drugs that activate plasmin, such as **tissue plasminogen activators (tPAs)**, are used to break down clots. - Tranexamic acid specifically **inhibits plasminogen activation**, thereby preventing plasmin formation.

Q: Which of the following is an antipsychotic drug?

Flupenthixol. ***Flupenthixol*** - **Flupenthixol** is a **first-generation (typical) antipsychotic** used primarily for managing **schizophrenia** and other psychotic disorders. - It acts by blocking **dopamine D2 receptors** in the brain, reducing positive symptoms like **hallucinations and delusions**. *Rasagiline* - **Rasagiline** is a **monoamine oxidase-B (MAO-B) inhibitor** used in the treatment of **Parkinson's disease**. - It works by preventing the breakdown of **dopamine** in the brain, thereby improving motor symptoms, and is not an antipsychotic. *Clobazam* - **Clobazam** is a **benzodiazepine** primarily indicated for the treatment of **epilepsy** (specifically Lennox-Gastaut syndrome) and **anxiety**. - Its mechanism involves enhancing the effect of **GABA** in the brain, producing sedative and anticonvulsant effects, distinct from antipsychotic action. *Divalproex* - **Divalproex** is a combination product of **valproic acid** and **sodium valproate**, typically used as a **mood stabilizer** for **bipolar disorder**, an **antiepileptic**, and for **migraine prophylaxis**. - It modulates **GABAergic** transmission and sodium channels, but it is not classified as an antipsychotic drug.

Question 1

What is the drug of choice for bleeding oesophageal varices?

Accepted Answer

Octreotide

Answer

Ethanolamine oleate

Answer

Propanolol

Answer

Phytonadione

Question 2

Cytolytic activity of membrane attack complex is modulated by ?

Accepted Answer

Factor S (vitronectin)

Answer

Factor I

Answer

Factor B

Answer

Factor H

Question 3

Which among the following is an absolute contraindication of Hormone replacement therapy?

Accepted Answer

Breast carcinoma

Answer

Endometriosis

Answer

Heart disease

Answer

Osteoarthritis

Question 4

Which of the following is the longest acting glucocorticoid?

Accepted Answer

Dexamethasone

Answer

Prednisone

Answer

Prednisolone

Answer

Cortisone

Question 5

Which of the following is the most potent topical corticosteroid?

Accepted Answer

Clobetasol propionate

Answer

Triamcinolone acetonide

Answer

Hydrocortisone acetate

Answer

Betamethasone valerate

Question 6

Which of the following reduces the efficacy of oral contraceptives?

Accepted Answer

Griseofulvin

Answer

Disulfiram

Answer

Erythromycin

Answer

Cimetidine

Question 7

Which of the following is a tricyclic antidepressant?

Accepted Answer

Doxepin

Answer

Fluoxetine

Answer

Citalopram

Answer

Venlafaxine

Question 8

Which of the following is a classic tricyclic antidepressant (TCA) commonly used as the prototype for the class?

Accepted Answer

Amitriptyline

Answer

Citalopram

Answer

Venlafaxine

Answer

Nortriptyline

Question 9

Mechanism of action of tranexamic acid is

Accepted Answer

Prevents fibrinolysis

Answer

Decrease vascular permeability

Answer

Smooth muscle contraction

Answer

Activates Plasmin formation

Question 10

Which of the following is an antipsychotic drug?

Accepted Answer

Flupenthixol

Answer

Rasagiline

Answer

Clobazam

Answer

Divalproex

NEET-PG 2013

Internal Medicine

Microbiology

Obstetrics and Gynecology

Pharmacology