Drugs for Dementia Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Drugs for Dementia. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Drugs for Dementia Indian Medical PG Question 1: A 60-year-old man with Alzheimer's disease has been started on donepezil. What is the primary mechanism of action of this medication?
- A. NMDA receptor antagonist
- B. Acetylcholinesterase inhibitor (Correct Answer)
- C. Dopamine receptor antagonist
- D. Serotonin reuptake inhibitor
Drugs for Dementia Explanation: ***Acetylcholinesterase inhibitor***
- Donepezil **blocks the enzyme acetylcholinesterase**, which is responsible for breaking down acetylcholine [1], [2].
- By inhibiting this enzyme, donepezil **increases the levels of acetylcholine** in the brain, improving **cholinergic neurotransmission** in patients with Alzheimer's disease [2].
*NMDA receptor antagonist*
- **NMDA receptor antagonists** like **memantine** work by blocking the activity of glutamate at the NMDA receptor, which is thought to reduce excitotoxicity in Alzheimer's [1], [3].
- This mechanism is different from donepezil, which targets the **cholinergic system** [1].
*Dopamine receptor antagonist*
- **Dopamine receptor antagonists** are primarily used in conditions like **schizophrenia** or **Parkinson's disease** (for psychotic symptoms), by blocking dopamine receptors.
- This is not the mechanism of action for medications used to treat cognitive symptoms of Alzheimer's disease.
*Serotonin reuptake inhibitor*
- **Serotonin reuptake inhibitors (SSRIs)** are a class of antidepressants that increase serotonin levels in the brain by blocking its reuptake [3].
- While depression can co-occur with Alzheimer's, SSRIs do not directly address the cognitive decline associated with the disease [3].
Drugs for Dementia Indian Medical PG Question 2: Which of the following is the most prominent clinical characteristic of Alzheimer's disease?
- A. Memory loss (Correct Answer)
- B. Neurofibrillary tangles
- C. Amyloid plaques
- D. Resting tremor
Drugs for Dementia Explanation: ***Memory loss***
- **Memory loss**, particularly of recent events (anterograde amnesia), is the **earliest and most prominent clinical symptom** of Alzheimer's disease.
- This is a **clinical characteristic** - an observable symptom experienced by the patient and noted by clinicians during evaluation.
- The memory deficit progressively worsens, initially affecting **short-term recall** and learned information, eventually extending to long-term memory and significantly impacting daily functioning.
*Neurofibrillary tangles*
- **Neurofibrillary tangles**, composed of hyperphosphorylated tau protein, are a **pathological hallmark** found in the brains of Alzheimer's patients at autopsy or biopsy.
- These are **microscopic findings**, not a clinical characteristic - they cannot be observed directly by the patient or clinician during clinical evaluation.
- Essential for definitive neuropathological diagnosis but not a clinical symptom.
*Amyloid plaques*
- **Amyloid plaques** (senile plaques), formed by aggregation of beta-amyloid peptides, are another **pathological hallmark** of Alzheimer's disease.
- Like neurofibrillary tangles, these are **microscopic neuropathological findings**, not observable clinical symptoms.
- They represent the underlying disease pathology but not the clinical presentation.
*Resting tremor*
- A **resting tremor** is a cardinal motor symptom of **Parkinson's disease**, not Alzheimer's disease.
- While some patients with advanced Alzheimer's may develop motor symptoms, resting tremor is **not a characteristic or prominent feature** of Alzheimer's disease.
- This option tests knowledge of differential diagnosis between neurodegenerative disorders.
Drugs for Dementia Indian Medical PG Question 3: Which of the following is the most appropriate treatment for an overactive bladder in a patient with dementia?
- A. Tolterodine (Correct Answer)
- B. Mirabegron
- C. Behavioral therapy/bladder training
- D. Oxybutynin
- E. Trospium
Drugs for Dementia Explanation: ***Tolterodine***
- **Tolterodine** is a **muscarinic antagonist** that blocks acetylcholine receptors in the bladder, reducing detrusor muscle contractions and overactive bladder symptoms.
- Unlike some other anticholinergics like oxybutynin, it has a **lower propensity to cross the blood-brain barrier** and thus a reduced risk of exacerbating cognitive impairment in patients with dementia.
*Mirabegron*
- **Mirabegron** is a **beta-3 adrenergic agonist** that relaxes the detrusor muscle, increasing bladder capacity.
- While it has a different mechanism of action and is less likely to cause anticholinergic cognitive side effects than older anticholinergics, it can still cause **hypertension** and **tachycardia**, which may be problematic in elderly patients with comorbidities.
*Behavioral therapy/bladder training*
- **Behavioral therapy** and **bladder training** are important first-line treatments for overactive bladder.
- However, for patients with **dementia**, cognitive impairment often makes adherence to and understanding of these complex therapies challenging or impossible without significant caregiver support.
*Oxybutynin*
- **Oxybutynin** is an **anticholinergic drug** that is effective for overactive bladder.
- However, it has a **high affinity for muscarinic receptors** in the brain and readily crosses the blood-brain barrier, significantly increasing the risk of **cognitive impairment, confusion, and delirium** in elderly patients, especially those with pre-existing dementia.
*Trospium*
- **Trospium** is a **quaternary amine anticholinergic** that is hydrophilic and has minimal blood-brain barrier penetration.
- While theoretically safer than oxybutynin in terms of CNS effects, it has **lower bladder selectivity** compared to tolterodine and may cause more peripheral anticholinergic side effects (dry mouth, constipation).
Drugs for Dementia Indian Medical PG Question 4: True about dementia is:
- A. Dementia due to atherosclerosis progresses in the same gradual manner as Alzheimer's disease
- B. Alzheimer's disease is due to multiple small strokes in the cerebral cortex
- C. Alzheimer's disease is associated with an increase in ACh release in the cerebral cortex
- D. Dementia involves a decline in memory and other cognitive functions affecting daily living (Correct Answer)
Drugs for Dementia Explanation: ***Dementia involves a decline in memory and other cognitive functions affecting daily living***
- This statement accurately defines **dementia** as a significant decline in **cognitive functions**, including memory, language, problem-solving, and executive function, severe enough to interfere with daily activities.
- The progressive nature of this decline leads to impaired independence and functional disability.
*Dementia due to atherosclerosis progresses in the same gradual manner as Alzheimer's disease*
- **Vascular dementia**, often caused by atherosclerosis leading to stroke or chronic cerebral ischemia, typically has a **stepped or fluctuating progression** rather than the gradual, continuous decline seen in Alzheimer's disease.
- This is a key distinguishing feature between vascular dementia and Alzheimer's disease.
*Alzheimer's disease is due to multiple small strokes in the cerebral cortex*
- This describes **vascular dementia**, which is distinct from Alzheimer's disease.
- **Alzheimer's disease** is characterized by the accumulation of **amyloid plaques** and **neurofibrillary tangles** in the brain, not by strokes.
*Alzheimer's disease is associated with an increase in ACh release in the cerebral cortex*
- **Alzheimer's disease** is associated with a significant **reduction in acetylcholine (ACh) levels** in the cerebral cortex, particularly in regions vital for memory and learning.
- Many treatments for Alzheimer's aim to inhibit **acetylcholinesterase**, thereby increasing ACh availability to compensate for this deficit.
Drugs for Dementia Indian Medical PG Question 5: A patient has a history of vomiting and was given an antiemetic. The patient subsequently developed abnormal movements (likely extrapyramidal symptoms or dystonia). What medication should be given to manage these abnormal movements?
- A. Hyoscine
- B. Methyl dopa
- C. Benzhexol (Correct Answer)
- D. Cyproheptadine
- E. Diphenhydramine
Drugs for Dementia Explanation: ***Benzhexol***
- **Extrapyramidal symptoms (EPS)** and **dystonia** are often caused by dopamine receptor blockade, and **anticholinergic medications** like benzhexol help restore the **dopamine-acetylcholine balance**.
- Benzhexol is a **muscarinic antagonist** that effectively reduces drug-induced Parkinsonism, dystonia, and akathisia by acting centrally.
- It is the **preferred oral agent** for ongoing management of drug-induced movement disorders.
*Diphenhydramine*
- Diphenhydramine is an **antihistamine** with **anticholinergic properties** that can be used for **acute dystonic reactions**, particularly when given parenterally (IV/IM).
- While effective for acute management, benzhexol is generally preferred for **ongoing oral therapy** and has more potent central anticholinergic effects.
*Hyoscine*
- While hyoscine is also an **anticholinergic agent**, it is primarily used for preventing **motion sickness** and managing **postoperative nausea and vomiting**.
- Its efficacy in reversing acute extrapyramidal symptoms induced by neuroleptics or antiemetics is generally **less pronounced** compared to agents like benzhexol.
*Methyl dopa*
- Methyl dopa is an **alpha-2 adrenergic agonist** primarily used in the treatment of **hypertension**, especially in pregnancy.
- It works by reducing sympathetic outflow and is **not indicated** for managing extrapyramidal symptoms or dystonia.
*Cyproheptadine*
- Cyproheptadine is an **antihistamine** with **serotonin antagonist** properties, used to treat allergic reactions, appetite stimulation, and occasionally **serotonin syndrome**.
- It does not have significant anticholinergic effects that would alleviate medication-induced extrapyramidal symptoms or dystonia.
Drugs for Dementia Indian Medical PG Question 6: Match the following drugs in Column A with their contraindications in Column B.
| Column A | Column B |
| :-- | :-- |
| 1. Morphine | 1. QT prolongation |
| 2. Amiodarone | 2. Thromboembolism |
| 3. Vigabatrin | 3. Pregnancy |
| 4. Estrogen preparations | 4. Head injury |
- A. A-1, B-3, C-2, D-4
- B. A-4, B-1, C-3, D-2 (Correct Answer)
- C. A-3, B-2, C-4, D-1
- D. A-2, B-4, C-1, D-3
Drugs for Dementia Explanation: ***A-4, B-1, C-3, D-2***
- **Morphine** is contraindicated in **head injury** as it can increase intracranial pressure and mask neurological symptoms.
- **Amiodarone** is contraindicated in patients with **QT prolongation** due to its risk of inducing more severe arrhythmias like Torsades de Pointes.
- **Vigabatrin** is contraindicated during **pregnancy** due to its potential for teratogenicity and adverse effects on fetal development.
- **Estrogen preparations** are contraindicated in patients with a history of **thromboembolism** due to their increased risk of blood clot formation.
*A-1, B-3, C-2, D-4*
- This option incorrectly matches **Morphine** with QT prolongation and **Estrogen preparations** with head injury, which are not their primary contraindications.
- It also incorrectly links **Vigabatrin** with thromboembolism and **Amiodarone** with pregnancy.
*A-3, B-2, C-4, D-1*
- This choice incorrectly associates **Morphine** with pregnancy and **Vigabatrin** with head injury, which are not the most critical or direct contraindications.
- It also misaligns **Amiodarone** with thromboembolism and **Estrogen preparations** with QT prolongation.
*A-2, B-4, C-1, D-3*
- This option incorrectly matches **Morphine** with thromboembolism and **Amiodarone** with head injury, which are not their most significant contraindications.
- It also incorrectly links **Vigabatrin** with QT prolongation and **Estrogen preparations** with pregnancy.
Drugs for Dementia Indian Medical PG Question 7: The use of levodopa is avoided in which of the following patients?
- A. Amyotrophic lateral sclerosis
- B. Psychosis (Correct Answer)
- C. Alzheimer's disease
- D. Essential tremor
Drugs for Dementia Explanation: ***Psychosis***
- Levodopa increases **dopaminergic activity** in the brain, which can significantly worsen or induce **psychotic symptoms** like hallucinations and delusions.
- Patients with pre-existing psychosis or a history of psychotic episodes are at high risk, making levodopa a **contraindicated** treatment.
*Alzheimer's disease*
- While Alzheimer's patients may experience motor symptoms, levodopa is generally not avoided unless there are specific **parkinsonian features** responsive to dopamine.
- The primary symptoms of Alzheimer's are **cognitive decline**, which levodopa does not treat and could potentially worsen agitation or confusion in advanced stages.
*Amyotrophic lateral sclerosis*
- **ALS** is a progressive neurodegenerative disease affecting motor neurons, leading to muscle weakness and atrophy.
- Levodopa is **not effective** in treating ALS because the disease pathology does not involve dopamine deficiency.
*Essential tremor*
- Essential tremor is a movement disorder primarily treated with **beta-blockers** or **anti-seizure medications**.
- Levodopa has **no established efficacy** in treating essential tremor, and its use is unrelated to its pathophysiology.
Drugs for Dementia Indian Medical PG Question 8: Which drug can cause psychosis?
- A. Ofloxacin
- B. Amfetamine (Correct Answer)
- C. Capreomycin
- D. Rifampicin
Drugs for Dementia Explanation: ### Explanation
**Correct Option: B. Amfetamine**
Amfetamine is a potent CNS stimulant that acts primarily by increasing the release of biogenic amines, particularly **Dopamine**, from presynaptic nerve terminals. According to the **Dopamine Hypothesis of Schizophrenia**, excessive dopaminergic activity in the mesolimbic pathway is linked to psychotic symptoms. High doses or chronic use of amfetamines can induce a "stimulant psychosis" that clinically mimics paranoid schizophrenia, characterized by delusions, hallucinations, and stereotypic behavior.
**Analysis of Incorrect Options:**
* **A. Ofloxacin:** While fluoroquinolones can occasionally cause CNS side effects like insomnia or dizziness, they are not classically associated with inducing frank psychosis.
* **C. Capreomycin:** This is a polypeptide protein synthesis inhibitor used in MDR-TB. Its primary toxicities are **nephrotoxicity** and **ototoxicity** (8th cranial nerve damage), similar to aminoglycosides.
* **D. Rifampicin:** A key anti-tubercular drug known for causing orange-colored secretions (urine, sweat, tears) and hepatotoxicity. It does not have psychotropic side effects.
**High-Yield Clinical Pearls for NEET-PG:**
* **Other drugs causing psychosis:** Levodopa (dopamine precursor), Steroids ("Steroid Psychosis"), Isoniazid (INH), Ketamine, and Cocaine.
* **Drug of Choice for Amfetamine Psychosis:** Antipsychotics like **Haloperidol** (D2 blockers) are used to manage acute symptoms.
* **Mechanism Recap:** Amfetamines reverse the direction of the dopamine transporter (DAT), pumping dopamine out into the synapse.
Drugs for Dementia Indian Medical PG Question 9: Which of the following drugs is most commonly associated with extrapyramidal side effects?
- A. Risperidone
- B. Haloperidol (Correct Answer)
- C. Clozapine
- D. Ziprasidone
Drugs for Dementia Explanation: **Explanation:**
The correct answer is **Haloperidol**.
**1. Why Haloperidol is correct:**
Haloperidol is a **First-Generation Antipsychotic (FGA)** or "Typical" antipsychotic. Its primary mechanism of action is the potent, non-selective blockade of **D2 receptors** in the brain. Extrapyramidal side effects (EPS) occur due to the blockade of D2 receptors in the **nigrostriatal pathway** [1], [3]. Haloperidol has a very high affinity for these receptors and dissociates slowly, leading to a high incidence of acute dystonia, akathisia, parkinsonism, and tardive dyskinesia [1], [3].
**2. Why the other options are incorrect:**
* **Clozapine:** This is the prototype **Second-Generation Antipsychotic (SGA)**. It has a low affinity for D2 receptors and a high affinity for 5-HT2A receptors. It is the drug with the **lowest risk of EPS** among all antipsychotics [2].
* **Risperidone:** While an SGA, it is "atypical" only at low doses. At higher doses (>6mg), it behaves like a typical antipsychotic and can cause EPS, but the risk remains lower than that of Haloperidol [2].
* **Ziprasidone:** An SGA with a lower propensity for EPS and weight gain, though it is more notably associated with QT interval prolongation.
**High-Yield Clinical Pearls for NEET-PG:**
* **EPS Hierarchy:** Haloperidol (Highest risk) > Risperidone > Olanzapine > Quetiapine > Clozapine (Lowest risk).
* **Drug of Choice for EPS:** Centrally acting anticholinergics like **Benztropine** or **Trihexyphenidyl (PACANE)** [3].
* **Tardive Dyskinesia:** The most serious long-term EPS; treatment involves switching to Clozapine or using VMAT-2 inhibitors (Valbenazine).
* **Hyperprolactinemia:** Also caused by D2 blockade in the tuberoinfundibular pathway; Haloperidol and Risperidone are common culprits [1], [3].
Drugs for Dementia Indian Medical PG Question 10: Which of the following drug classes is known to cause extrapyramidal symptoms?
- A. Antibiotics
- B. Salicylates
- C. Barbiturates
- D. Phenothiazines (Correct Answer)
Drugs for Dementia Explanation: **Explanation:**
**1. Why Phenothiazines are correct:**
Phenothiazines (e.g., Chlorpromazine, Fluphenazine) are "Typical" or first-generation antipsychotics. Their primary mechanism of action is the **blockade of Dopamine (D2) receptors** in the brain. While blockade in the mesolimbic pathway treats psychosis, blockade in the **nigrostriatal pathway** disrupts the balance between dopamine and acetylcholine. This deficiency of dopamine in the basal ganglia leads to **Extrapyramidal Symptoms (EPS)**, including acute dystonia, akathisia, parkinsonism, and tardive dyskinesia.
**2. Why other options are incorrect:**
* **Antibiotics:** Generally do not affect dopaminergic pathways. While some (like aminoglycosides) have neuromuscular blocking properties, they do not cause EPS.
* **Salicylates:** These are NSAIDs (e.g., Aspirin) that inhibit cyclooxygenase (COX) enzymes. Toxicity typically presents with tinnitus, metabolic acidosis, and respiratory alkalosis, not movement disorders.
* **Barbiturates:** These act as GABA-A receptor agonists (CNS depressants). Overdose leads to respiratory depression and coma, but they do not block dopamine receptors.
**3. NEET-PG High-Yield Pearls:**
* **Drug of Choice for Acute Dystonia:** Central anticholinergics like **Promethazine** or **Benztropine**.
* **Drug of Choice for Akathisia:** **Propranolol** (Beta-blocker).
* **Tardive Dyskinesia:** Result of dopamine receptor supersensitivity; managed by switching to **Clozapine** (least likely to cause EPS) or using VMAT-2 inhibitors (Valbenazine).
* **Antiemetic EPS:** Remember that **Metoclopramide** (a D2 blocker) is a common non-psychiatric cause of EPS.
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