photo-1783940238376.jpg
Tell me answers of these
Reading File
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Here are the answers to all 10 questions, with explanations:
SECTION A - Pharmacology MCQ Answers
1. Tolerance and drug resistance can be a consequence of:
Answer: (a) Change in receptors, loss of them or exhaustion of mediators
Pharmacodynamic tolerance occurs due to receptor downregulation/desensitization, loss of receptors, or depletion of mediators. Increased receptor sensitivity (b) would be the opposite. Decreased metabolic degradation (c) would increase drug effect, not cause tolerance.
2. Which atropine substitute is used in treatment of overactive bladder?
Answer: (a) Flavoxate
Flavoxate is an antimuscarinic/antispasmodic used specifically for overactive bladder (urinary urgency, frequency). Homatropine is used for ophthalmology; Scopolamine for motion sickness; Ipratropium bromide for COPD/asthma.
3. Sympathomimetic drug used as nasal decongestant AND vasopressor:
Answer: (b) Phenylephrine
Phenylephrine is a selective alpha-1 agonist used both as a nasal decongestant (topical/oral) and as a vasopressor in hypotension. Epinephrine acts on alpha+beta; Norepinephrine is mainly a vasopressor; Ephedrine also has both uses but phenylephrine is the classic answer here.
4. 55-year-old woman on antihypertensive with rash and cough:
Answer: (d) Enalapril
This is a classic presentation of ACE inhibitor side effects - dry cough (in 5-10% of patients) and skin rash. Enalapril is an ACE inhibitor. Atenolol (beta-blocker), Prazosin (alpha-blocker), and Chlorthalidone (thiazide diuretic) do not cause this combination of symptoms. Confirmed by Goodman & Gilman's.
5. Anti-anginal drug inhibiting If (funny) current in SA node:
Answer: (a) Ivabradine
Ivabradine is a selective blocker of the hyperpolarization-activated "funny" current (If) in the SA node, slowing heart rate. Confirmed by Katzung's Basic and Clinical Pharmacology. Ranolazine inhibits late Na+ current; Trimetazidine inhibits fatty acid oxidation; Nicorandil opens K-ATP channels.
6. Monitoring of Low Molecular Weight Heparin (LMWH) therapy:
Answer: (d) Does not require monitoring
LMWH (e.g., enoxaparin) has predictable pharmacokinetics and does NOT routinely require monitoring. This is confirmed by multiple textbooks - "most patients do not need daily drug activity monitoring." Anti-Xa levels may be checked in special cases (renal failure, pregnancy, extreme weights), but routine monitoring is not needed. aPTT (b) is used for unfractionated heparin.
7. Anti-hyperlipidemic agent preferred in pregnancy:
Answer: (b) Colesvelam
Statins (including Pravastatin) are contraindicated in pregnancy (teratogenic). Bile acid sequestrants like Colesvelam/Cholestyramine are not absorbed systemically and are safe in pregnancy. Niacin and Fenofibrate are also avoided in pregnancy.
8. Drug of choice for low output heart failure due to atrial fibrillation:
Answer: (b) Digoxin
Digoxin is the drug of choice when heart failure is accompanied by atrial fibrillation, as it slows the ventricular rate (negative chronotropy) and provides positive inotropy to improve cardiac output. Confirmed by Goodman & Gilman's (digoxin for heart failure + atrial fibrillation).
9. Torsemide acts by inhibiting in the renal tubular cell:
Answer: (a) Na+-K+-2Cl- cotransporter
Torsemide is a loop diuretic. All loop diuretics act by inhibiting the Na+-K+-2Cl- cotransporter (NKCC2) in the thick ascending limb of the Loop of Henle. This is the same mechanism as furosemide and bumetanide.
10. Primary mechanism by which prostaglandins promote ulcer healing:
Answer: (b) Augmentation of bicarbonate buffered mucus layer covering gastroduodenal mucosa
Prostaglandins (especially PGE2) promote ulcer healing primarily by stimulating mucus and bicarbonate secretion, enhancing the mucosal protective barrier. While they do inhibit gastric acid secretion, the PRIMARY mechanism for ulcer healing is mucosal defense via the bicarbonate-buffered mucus layer. Confirmed by Tintinalli's and Harrison's.
Quick Summary Table
| Q | Answer | Key Point |
|---|---|---|
| 1 | (a) | Receptor loss/downregulation/mediator exhaustion |
| 2 | (a) Flavoxate | Specific for overactive bladder |
| 3 | (b) Phenylephrine | Alpha-1 selective - decongestant + vasopressor |
| 4 | (d) Enalapril | ACE inhibitor - cough + rash |
| 5 | (a) Ivabradine | If current blocker in SA node |
| 6 | (d) No monitoring needed | Predictable PK of LMWH |
| 7 | (b) Colesvelam | Bile acid sequestrant - safe in pregnancy |
| 8 | (b) Digoxin | HF + AF = Digoxin |
| 9 | (a) Na+-K+-2Cl- | Loop diuretic mechanism |
| 10 | (b) Bicarbonate-mucus layer | Cytoprotective mechanism |
SECTION A - Answers
| Q | Answer | Explanation |
|---|---|---|
| 1 | (a) Change in receptors, loss of them or exhaustion of mediators | Pharmacodynamic tolerance = receptor downregulation, desensitization, or mediator depletion |
| 2 | (a) Flavoxate | Antimuscarinic/antispasmodic used specifically for overactive bladder |
| 3 | (b) Phenylephrine | Selective alpha-1 agonist - used as both nasal decongestant and vasopressor |
| 4 | (d) Enalapril | ACE inhibitors cause dry cough (5-10%) + skin rash - classic side effects |
| 5 | (a) Ivabradine | Selective If ("funny" current) blocker in SA node - pure heart rate reduction |
| 6 | (d) Does not require monitoring | LMWH has predictable pharmacokinetics; anti-Xa only in special cases (renal failure, pregnancy) |
| 7 | (b) Colesvelam | Bile acid sequestrant - not systemically absorbed, safe in pregnancy; statins are contraindicated |
| 8 | (b) Digoxin | Drug of choice when low-output HF is combined with AF - slows AV conduction + positive inotropy |
| 9 | (a) Na⁺-K⁺-2Cl⁻ cotransporter | Loop diuretics (torsemide, furosemide) inhibit NKCC2 in thick ascending limb of Loop of Henle |
| 10 | (b) Augmentation of bicarbonate buffered mucus layer covering gastroduodenal mucosa | Primary cytoprotective mechanism of prostaglandins - mucosal defense via mucus/bicarbonate barrier |
Key High-Yield Points to Remember
- Q2 - Overactive bladder drugs: Flavoxate, Oxybutynin, Solifenacin, Tolterodine (NOT scopolamine or ipratropium)
- Q4 - ACE inhibitor cough is due to bradykinin accumulation; switch to ARB if cough is problematic
- Q5 - Ivabradine is the ONLY If current blocker; useful in HF + angina without affecting BP or contractility
- Q6 - LMWH vs UFH: UFH needs aPTT monitoring; LMWH does NOT (routine)
- Q7 - In pregnancy, only bile acid sequestrants (Cholestyramine, Colesevelam) are permitted for hyperlipidemia
- Q8 - Digoxin is specifically favored in HF with AF because it controls ventricular rate AND improves cardiac outputThese are Questions 11-20 (Section A continuation). Here are the answers:
Questions 11–20 Answers
11. β blocker with β1 selectivity + intrinsic sympathomimetic activity (ISA) + membrane stabilizing property:
Answer: (c) Acebutolol
| Drug | β1 selective | ISA | Membrane stabilizing |
|---|---|---|---|
| Carvedilol | No (α+β) | No | No |
| Atenolol | Yes | No | No |
| Acebutolol | Yes | Yes | Yes |
| Metoprolol | Yes | No | No |
Acebutolol is the only beta-blocker with ALL THREE properties.
12. Characteristics of Carvedilol - ALL EXCEPT:
Answer: (a) It is a beta1-selective antagonist
Carvedilol is NON-selective (blocks β1, β2, and α1). All the other statements are TRUE about carvedilol - it does have alpha1 + beta blocking effects (b), it does attenuate free radical lipid peroxidation (c), and it does inhibit vascular smooth muscle mitogenesis (d).
13. Aminocaproic acid is drug of choice for:
Answer: (b) Bleeding from fibrinolytic therapy
Aminocaproic acid (and tranexamic acid) are antifibrinolytics - they inhibit plasminogen activators. They are specifically used to reverse/treat excessive bleeding caused by fibrinolytic (thrombolytic) therapy.
14. Statin that can be administered any time in 24 hours:
Answer: (a) Rosuvastatin
- Statins with SHORT half-lives (Simvastatin, Lovastatin) must be given at NIGHT (when cholesterol synthesis peaks)
- Statins with LONG half-lives (Rosuvastatin ~19h, Atorvastatin ~14h) can be given at ANY time of day
- Among the options, Rosuvastatin has the longest half-life and can be taken at any time
15. Thiazide diuretics do NOT potentiate the antihypertensive action of:
Answer: (b) Nifedipine
Thiazides potentiate (work synergistically with) most antihypertensives because they reduce plasma volume. However, nifedipine (dihydropyridine CCB) works via a different mechanism and thiazides are not known to potentiate its action in the same way. Thiazides classically potentiate metoprolol (beta-blocker), hydralazine, and captopril (ACE inhibitor).
16. Tolerance to this inotropic drug develops after a few days:
Answer: (a) Amrinone
Amrinone (a PDE-3 inhibitor / phosphodiesterase inhibitor) is known to develop tachyphylaxis/tolerance within days. It is now largely replaced by milrinone. Dobutamine can also develop tolerance but amrinone is the classic textbook answer for rapid tolerance.
17. Mechanism of stimulant purgatives is:
Answer: (b) Increasing motility and secretion
Stimulant laxatives (e.g., bisacodyl, senna, castor oil) act by:
- Irritating intestinal mucosa
- Stimulating peristaltic motility
- Increasing secretion of water and electrolytes into the bowel
- (a) is bulk-forming laxatives; (c) is stool softeners; (d) is osmotic laxatives
18. All physiologic reactions involved in control of bleeding EXCEPT:
Answer: (c) Activation of the antifibrinolytic system
The normal hemostatic response involves:
- Platelet adhesion (a) ✓
- Platelet release reaction (b) ✓
- Triggering of coagulation (d) ✓
The antifibrinolytic system is NOT a primary physiologic control of bleeding - rather, fibrinolysis (clot breakdown) is normal physiology; antifibrinolytics are pharmacological agents. The body activates fibrinolysis, not antifibrinolysis, as a normal process.
19. Gynaecomastia can occur as side effect of:
Answer: (b) Cimetidine
Cimetidine (H2 blocker) causes gynaecomastia by:
- Blocking androgen receptors
- Inhibiting testosterone synthesis
- Increasing prolactin levels
Bromocriptine actually TREATS gynaecomastia. Famotidine and Levodopa do not cause it.
20. Most important drawback of sucralfate in duodenal ulcer:
Answer: (d) Need for taking a big tablet four times a day
Sucralfate is actually effective in healing ulcers (rules out a), provides good pain relief (rules out b), and has very few side effects - mainly constipation (rules out c). The main practical drawback is compliance - it must be taken as a large tablet 4 times daily, before meals and at bedtime, on an empty stomach.
Summary Table
| Q | Answer | Key Point |
|---|---|---|
| 11 | (c) Acebutolol | β1 selective + ISA + membrane stabilizing - all 3 properties |
| 12 | (a) Beta1-selective - FALSE | Carvedilol is non-selective (α1+β1+β2) |
| 13 | (b) Bleeding from fibrinolytic therapy | Antifibrinolytic agent |
| 14 | (a) Rosuvastatin | Longest half-life - any time dosing |
| 15 | (b) Nifedipine | CCB - not potentiated by thiazides |
| 16 | (a) Amrinone | PDE inhibitor - rapid tachyphylaxis |
| 17 | (b) Increasing motility and secretion | Irritant/stimulant mechanism |
| 18 | (c) Antifibrinolytic system | Body activates fibrinolysis, not antifibrinolysis |
| 19 | (b) Cimetidine | Anti-androgenic + prolactin elevation |
| 20 | (d) Big tablet four times a day | Compliance issue - main practical drawback |
This is a shared conversation. Sign in to Orris to start your own chat.