I don't see any questions or attachments in your message. Could you please share the questions you'd like me to answer?Here are the answers to all 10 MCQs from the Department of Pharmacology Pre-Final Examination:

1. The local anaesthetic having high cardiotoxic and arrhythmogenic potential is ✅ C. Bupivacaine

Bupivacaine is notorious for severe cardiotoxicity - it blocks cardiac Na⁺ channels with high affinity and slow dissociation, causing refractory ventricular arrhythmias and cardiac arrest. Ropivacaine was developed specifically to be less cardiotoxic.

2. Gynaecomastia can occur as a side effect of ✅ B. Cimetidine

Cimetidine is an H₂ blocker that also acts as an anti-androgen - it blocks androgen receptors and inhibits testosterone synthesis, leading to gynaecomastia. Famotidine does not have this effect.

3. The chelating agent of choice for acute arsenic poisoning is ✅ B. Succimer (DMSA)

Succimer (2,3-dimercaptosuccinic acid) is the current drug of choice for acute arsenic poisoning. It is a water-soluble analogue of BAL with fewer side effects. BAL (Dimercaprol) is the older choice but DMSA is now preferred.

4. The drug of choice for trigeminal neuralgia is ✅ C. Carbamazepine

Carbamazepine is the first-line drug for trigeminal neuralgia. It blocks voltage-gated Na⁺ channels, reducing abnormal neuronal firing in the trigeminal nerve. It is highly effective and specifically indicated for this condition.

5. Which of the following is an irreversible inhibitor of cyclooxygenase? ✅ A. Aspirin

Aspirin irreversibly acetylates and inactivates both COX-1 and COX-2. All other NSAIDs (phenylbutazone, indomethacin, piroxicam) are reversible competitive inhibitors. This is why aspirin's antiplatelet effect lasts the entire platelet lifespan (~7-10 days).

6. Glomerular filtration of a drug is affected by its ✅ B. Plasma protein binding

Only free (unbound) drug is filtered at the glomerulus. Drugs heavily bound to plasma proteins (albumin, etc.) cannot be filtered. Lipid solubility, ionization, and tubular secretion affect reabsorption/secretion, not GFR.

7. Select the ergot compound which is primarily used for dementia ✅ C. Codergocrine (co-dergocrine mesylate / Hydergine)

Codergocrine (ergoloid mesylates) is used in dementia/cognitive decline. Bromocriptine is for Parkinson's/prolactinoma, ergotamine for migraines, and methysergide for migraine prophylaxis.

8. Significant tolerance does NOT develop to the following action of morphine ✅ D. Miosis

Tolerance develops to analgesia, euphoria, sedation, respiratory depression, and nausea with chronic morphine use. However, miosis (pupillary constriction via stimulation of Edinger-Westphal nucleus) is resistant to tolerance - chronic opioid users still show pinpoint pupils.

9. The following drug is effective in chlorpromazine-induced parkinsonism ✅ A. Trihexyphenidyl

Chlorpromazine causes drug-induced parkinsonism by blocking D₂ receptors. Treatment uses anticholinergic drugs like trihexyphenidyl (benzhexol). Levodopa is avoided because it competes with the dopamine blockade, and selegiline/bromocriptine are not used for drug-induced parkinsonism.

10. First choice drug for open angle glaucoma is ✅ C. Ocular prostaglandin analogues (e.g., latanoprost)

Current guidelines designate prostaglandin analogues (latanoprost, bimatoprost, travoprost) as first-line therapy for open-angle glaucoma due to superior IOP reduction (25-35%), once-daily dosing, and good tolerability. Beta-blockers were the traditional first choice but prostaglandins have now replaced them in most guidelines.