Psychopharmacology — MCQs

Psychopharmacology Indian Medical PG Practice Questions and MCQs

Question 161: Which of the following is not associated with neuroleptic malignant syndrome?

A. Haloperidol
B. Metoclopramide
C. Domperidone
D. Amantadine (Correct Answer)

Explanation: **Explanation:** Neuroleptic Malignant Syndrome (NMS) is a life-threatening idiosyncratic reaction to **dopamine antagonists**. The pathophysiology involves a massive blockade of central dopamine receptors (D2), leading to the classic tetrad of hyperthermia, muscular "lead-pipe" rigidity, autonomic instability, and altered mental status. **Why Amantadine is the correct answer:** Amantadine is a **dopaminergic agonist** (it increases dopamine release and inhibits reuptake). It is used to treat Parkinson’s disease and extrapyramidal symptoms. Because NMS is caused by a *deficiency* of dopamine activity, Amantadine is actually used as a **treatment** for NMS, not a cause. Importantly, the **sudden withdrawal** of Amantadine (or Levodopa) can precipitate NMS. **Analysis of Incorrect Options:** * **Haloperidol:** A high-potency typical antipsychotic and the most common culprit associated with NMS due to its strong D2 receptor antagonism. * **Metoclopramide:** Although used as an antiemetic, it is a central D2 receptor antagonist and is a well-known non-antipsychotic cause of NMS. * **Domperidone:** Like metoclopramide, it is a dopamine antagonist. While it primarily acts peripherally, it can cross the blood-brain barrier in certain conditions or high doses, potentially contributing to NMS. **NEET-PG High-Yield Pearls:** * **Key Lab Finding:** Significantly elevated **Creatine Phosphokinase (CPK)** levels and leukocytosis. * **Drug of Choice:** **Dantrolene** (muscle relaxant) is the specific treatment, often combined with **Bromocriptine** (dopamine agonist). * **Mnemonic (FEVER):** **F**ever, **E**ncephalopathy, **V**itals unstable, **E**levated enzymes (CPK), **R**igidity. * **Differential:** Unlike Serotonin Syndrome, NMS presents with "lead-pipe" rigidity and bradyreflexia, rather than hyperreflexia and myoclonus.

Question 162: What is a treatment for unipolar depression?

A. Fluoxetine
B. Sertraline
C. Citalopram
D. All of the above (Correct Answer)

Explanation: **Explanation:** The correct answer is **D. All of the above**. Unipolar depression (Major Depressive Disorder) is primarily managed using **Selective Serotonin Reuptake Inhibitors (SSRIs)** as the first-line pharmacological intervention. SSRIs work by inhibiting the presynaptic reuptake of serotonin (5-HT), thereby increasing its availability in the synaptic cleft. * **Fluoxetine (Option A):** A prototype SSRI with the longest half-life (due to its active metabolite, norfluoxetine). It is often the preferred choice in children and adolescents. * **Sertraline (Option B):** An SSRI known for its safety profile in patients with cardiovascular disease (post-MI). It has a lower risk of drug-drug interactions compared to fluoxetine. * **Citalopram (Option C):** A highly selective SSRI. While effective, it requires monitoring for dose-dependent QTc prolongation. Since all three medications belong to the SSRI class and are FDA-approved first-line treatments for unipolar depression, "All of the above" is the correct choice. **High-Yield Clinical Pearls for NEET-PG:** * **First-line for MDD:** SSRIs (due to better tolerability and lower toxicity in overdose compared to TCAs). * **Lag period:** Antidepressants typically take **2–4 weeks** to show clinical improvement. * **Side Effects:** Most common include GI upset, sexual dysfunction (most common long-term side effect), and sleep disturbances. * **Serotonin Syndrome:** A potential life-threatening complication when SSRIs are combined with MAOIs; characterized by the triad of autonomic instability, neuromuscular hyperactivity, and altered mental status. * **Discontinuation Syndrome:** Least common with Fluoxetine (due to long half-life) and most common with Paroxetine.

Question 163: Which of the following is NOT an anxiolytic drug?

A. Melatonin (Correct Answer)
B. Haloperidol
C. Alprazolam
D. Sertraline

Explanation: **Explanation:** The correct answer is **Melatonin**. Melatonin is a hormone produced by the pineal gland that regulates the sleep-wake cycle (circadian rhythm). While it is used clinically for insomnia and jet lag, it does not possess intrinsic anxiolytic (anxiety-reducing) properties. **Analysis of Options:** * **Alprazolam:** A Benzodiazepine (BZD) that acts as a positive allosteric modulator of the $GABA_A$ receptor. It is a classic, fast-acting anxiolytic used for panic disorders and generalized anxiety. * **Sertraline:** An SSRI (Selective Serotonin Reuptake Inhibitor). Although primarily classified as an antidepressant, SSRIs are the **first-line long-term treatment** for most anxiety disorders (GAD, Social Anxiety, Panic Disorder). * **Haloperidol:** A typical antipsychotic (D2 blocker). While its primary indication is psychosis, it is frequently used "off-label" in acute clinical settings as a chemical restraint to manage severe agitation and acute anxiety associated with delirium or psychosis. **High-Yield Clinical Pearls for NEET-PG:** * **First-line for Acute Anxiety:** Benzodiazepines (e.g., Alprazolam, Diazepam) due to immediate onset. * **First-line for Chronic Anxiety:** SSRIs (e.g., Sertraline, Escitalopram) due to better safety profiles and lack of dependence. * **Buspirone:** A 5-HT1A partial agonist; it is a pure anxiolytic that lacks sedative, hypnotic, or muscle relaxant properties. * **Propranolol:** Used for "Performance Anxiety" to control peripheral autonomic symptoms (tremors, tachycardia).

Question 164: "Wet Pillow Syndrome" is caused by

A. Imipramine
B. Bromocriptine
C. Clozapine (Correct Answer)
D. Amitriptyline

Explanation: **Explanation:** **Clozapine** is the correct answer. **"Wet Pillow Syndrome"** refers to **sialorrhea** (excessive salivation), which is a paradoxical and common side effect of Clozapine, occurring in up to 30–50% of patients. It is most prominent at night, leading to drooling that soaks the patient's pillow. * **Mechanism:** While Clozapine is an anticholinergic drug (which usually causes dry mouth), it causes sialorrhea likely through its **M4 receptor agonism** in the salivary glands and its **alpha-2 adrenergic antagonism**, which inhibits the swallowing reflex during sleep. * **Management:** It is often treated with peripheral anticholinergics like **Glycopyrrolate** or sublingual **Atropine** drops. **Why the other options are incorrect:** * **Imipramine & Amitriptyline (TCAs):** These are potent **muscarinic antagonists**. Their primary side effect is **Xerostomia** (dry mouth), the exact opposite of sialorrhea. * **Bromocriptine:** This is a dopamine agonist used in Parkinson’s and Prolactinomas. It does not typically cause excessive salivation; common side effects include nausea, orthostatic hypotension, and hallucinations. **High-Yield Clinical Pearls for NEET-PG:** * **Clozapine** is the "Gold Standard" for **Treatment-Resistant Schizophrenia**. * **Most Serious Side Effect:** Agranulocytosis (requires mandatory ANC monitoring). * **Most Common Side Effect:** Sedation. * **Most Common Cause of Death:** Myocarditis/Cardiomyopathy. * **Other Key Side Effects:** Lowers seizure threshold (dose-dependent), weight gain, and metabolic syndrome.

Question 165: Which of the following statements is true about neuroleptic malignant syndrome?

A. General antipsychotics are more associated with its development. (Correct Answer)
B. Symptoms include rigidity, fever, and altered consciousness.
C. Dantrolene is an effective treatment for improving symptoms.
D. Bromocriptine can be used in the management of neuroleptic malignant syndrome.

Explanation: **Explanation:** **Neuroleptic Malignant Syndrome (NMS)** is a rare but life-threatening idiosyncratic reaction to dopamine antagonists. **1. Why Option A is Correct:** While all antipsychotics can cause NMS, **First-Generation Antipsychotics (Typical/General Antipsychotics)** like Haloperidol and Fluphenazine are more frequently associated with its development due to their high potency and strong D2 receptor antagonism. High doses, rapid titration, and parenteral administration further increase this risk. **2. Analysis of Other Options:** * **Options B, C, and D:** While these statements are clinically **true** (NMS does present with the tetrad of rigidity, fever, autonomic instability, and altered sensorium; and Dantrolene/Bromocriptine are used for treatment), in the context of this specific MCQ format, Option A is highlighted as the primary pharmacological association being tested. *Note: In many standard exams, B, C, and D are also considered correct facts; however, the question likely seeks the most fundamental epidemiological association.* **3. Clinical Pearls for NEET-PG:** * **The Tetrad (FEVER):** **F**ever, **E**ncephalopathy (Altered mental status), **V**itals unstable (Autonomic instability), **E**levated enzymes (CPK), and **R**igidity ("Lead-pipe" variety). * **Pathophysiology:** Central D2 receptor blockade in the hypothalamus (fever) and basal ganglia (rigidity). * **Key Lab Finding:** Significantly elevated **Serum Creatine Phosphokinase (CPK)** and leukocytosis. * **Management:** 1. Immediate discontinuation of the offending agent (Most important step). 2. Supportive care (Hydration/Cooling). 3. **Dantrolene** (Muscle relaxant) or **Bromocriptine/Amantadine** (Dopamine agonists). * **Differential Diagnosis:** Serotonin Syndrome (presents with hyperreflexia and myoclonus, unlike the lead-pipe rigidity of NMS).

Question 166: What is the most common cardiac adverse effect of lithium?

A. Arrhythmia
B. Cardiomyopathy
C. Bradycardia (Correct Answer)
D. Hypotension

Explanation: **Explanation:** Lithium is the gold-standard mood stabilizer for Bipolar Disorder, but it has a narrow therapeutic index and significant multisystem side effects. **Why Bradycardia is the correct answer:** The most common cardiac manifestation of lithium therapy is **T-wave inversion or flattening** (similar to hypokalemia), which is usually benign. However, among the clinical cardiac adverse effects, **Sinus Bradycardia** and **Sinus Node Dysfunction (Sick Sinus Syndrome)** are the most frequently reported. Lithium interferes with the electrical conduction system of the heart by inhibiting the influx of sodium ions through the pacemaker channels, leading to a decrease in the firing rate of the sinoatrial (SA) node. **Analysis of Incorrect Options:** * **A. Arrhythmia:** While lithium can cause arrhythmias (like ventricular tachycardia) in cases of severe toxicity, they are less common than simple bradycardia at therapeutic or mildly toxic levels. * **B. Cardiomyopathy:** This is not a recognized side effect of lithium. Cardiomyopathy is more commonly associated with chronic alcohol use or certain antipsychotics (like Clozapine-induced myocarditis). * **D. Hypotension:** Lithium does not typically affect peripheral vascular resistance or blood pressure directly. **High-Yield NEET-PG Pearls:** * **ECG Changes:** T-wave flattening/inversion is the most common *electrocardiographic* finding (benign). * **Teratogenicity:** Lithium use in pregnancy is associated with **Ebstein’s Anomaly** (atrialization of the right ventricle). * **Monitoring:** Before starting lithium, baseline **ECG, Renal Function Tests (RFT), and Thyroid Function Tests (TFT)** are mandatory. * **Therapeutic Range:** 0.6–1.2 mEq/L (Prophylaxis: 0.6–0.8; Acute Mania: 0.8–1.2). Toxicity usually starts >1.5 mEq/L.

Question 167: Dryness of mouth is caused by antipsychotics due to their:

A. Anticholinergic action (Correct Answer)
B. Antiadrenergic action
C. Antidopaminergic action
D. Antihistaminic action

Explanation: **Explanation:** The correct answer is **A. Anticholinergic action**. **Mechanism of Action:** Antipsychotics (especially first-generation agents like Chlorpromazine and low-potency neuroleptics) often possess significant affinity for **Muscarinic (M1) receptors**. By blocking these receptors, they inhibit the parasympathetic nervous system's stimulation of the salivary glands. Since acetylcholine is the primary neurotransmitter responsible for inducing salivation, its antagonism leads to **Xerostomia** (dryness of mouth). **Analysis of Incorrect Options:** * **B. Antiadrenergic action:** Blockade of alpha-1 adrenergic receptors primarily leads to orthostatic hypotension, reflex tachycardia, and nasal congestion, rather than dry mouth. * **C. Antidopaminergic action:** This is the primary therapeutic mechanism of antipsychotics (D2 blockade). It is responsible for the antipsychotic effect and extrapyramidal side effects (EPS) like parkinsonism and dystonia, but not autonomic side effects like dry mouth. * **D. Antihistaminic action:** Blockade of H1 receptors is primarily associated with sedation and weight gain. **NEET-PG High-Yield Clinical Pearls:** * **Low-potency vs. High-potency:** Low-potency antipsychotics (e.g., Chlorpromazine, Thioridazine) have **higher** anticholinergic activity compared to high-potency drugs (e.g., Haloperidol). * **The "Anti-SLUDGE" Effect:** Anticholinergic side effects can be remembered by the mnemonic: Dry mouth, blurred vision (cycloplegia), constipation, and urinary retention. * **Clozapine Paradox:** While most antipsychotics cause dry mouth, **Clozapine** is unique because it often causes **Sialorrhea** (excessive salivation), likely due to its agonist action at M4 receptors or impairment of the swallowing reflex. * **Management:** Patients are often advised to use sugarless gum or frequent sips of water to manage xerostomia.

Question 168: What is the usual adult maintenance dose of Clozapine?

A. 150 mg
B. 250 mg
C. 300 mg (Correct Answer)
D. 500 mg

Explanation: **Explanation:** Clozapine is an atypical (second-generation) antipsychotic reserved for treatment-resistant schizophrenia. The correct answer is **300 mg**, as this represents the standard target maintenance dose for most adult patients to achieve therapeutic efficacy. **1. Why 300 mg is Correct:** The initiation of Clozapine requires slow titration to minimize side effects like orthostatic hypotension and seizures. While the starting dose is 12.5 mg once or twice daily, it is gradually increased by 25–50 mg/day. The **usual adult maintenance dose** typically ranges between **300 mg and 450 mg per day** (administered in divided doses). 300 mg is the established clinical benchmark for the lower end of the effective maintenance range. **2. Analysis of Incorrect Options:** * **150 mg (Option A):** This is generally considered a sub-therapeutic dose for maintenance in most adults, though it may be used during the titration phase or in elderly/sensitive patients. * **250 mg (Option B):** While closer to the target, it is still slightly below the standard 300–450 mg maintenance range defined in most pharmacological guidelines (e.g., Maudsley, FDA). * **500 mg (Option D):** While some patients require up to 600–900 mg (maximum limit), 500 mg is above the "usual" starting maintenance point and carries a higher risk of dose-dependent seizures. **High-Yield Clinical Pearls for NEET-PG:** * **Indication:** Treatment-resistant schizophrenia (failure of ≥2 antipsychotics, one being an atypical). * **Black Box Warning:** **Agranulocytosis** (requires mandatory WBC and ANC monitoring). * **Side Effects:** Sialorrhea (excessive salivation), sedation, weight gain, and lowering of the seizure threshold. * **Myocarditis:** A rare but fatal side effect; monitor for chest pain or tachycardia in the first month. * **Therapeutic Range:** Plasma levels >350 ng/mL are generally required for a response.

Question 169: All of the following are side effects of Clozapine except?

A. Agranulocytosis
B. Myocarditis
C. Seizures
D. Weight loss (Correct Answer)

Explanation: **Explanation:** Clozapine is a unique "atypical" antipsychotic reserved for treatment-resistant schizophrenia. The correct answer is **Weight loss** because Clozapine is actually associated with significant **weight gain** and metabolic syndrome. 1. **Why Weight Loss is the Correct Answer:** Clozapine has a high affinity for $H_1$ (histamine) and $5-HT_{2C}$ receptors. Blockade of these receptors leads to increased appetite and profound weight gain. It also carries the highest risk among antipsychotics for causing dyslipidemia and Type 2 Diabetes Mellitus. 2. **Analysis of Incorrect Options:** * **Agranulocytosis:** This is the most dreaded side effect (occurring in ~1%). It requires mandatory WBC and ANC (Absolute Neutrophil Count) monitoring. * **Myocarditis:** A rare but potentially fatal idiosyncratic reaction, usually occurring within the first 4–8 weeks of treatment. * **Seizures:** Clozapine reduces the seizure threshold in a dose-dependent manner. The risk is significantly higher at doses above 600 mg/day. **High-Yield Clinical Pearls for NEET-PG:** * **Sialorrhea (Drooling):** Paradoxically, though it has anticholinergic properties, Clozapine commonly causes excessive salivation (often nocturnal). * **Constipation:** It can cause life-threatening paralytic ileus due to potent anticholinergic effects. * **No EPS/Hyperprolactinemia:** Clozapine is unique because it rarely causes Extrapyramidal Side Effects or increases prolactin levels. * **DOC (Drug of Choice):** For treatment-resistant schizophrenia and schizophrenia with persistent suicidal behavior.

Question 170: What is the most common congenital anomaly associated with lithium use during pregnancy?

A. Cardiac malformations (Correct Answer)
B. Neural tube defects
C. Renal anomaly
D. Fetal hydantoin syndrome

Explanation: **Explanation:** **1. Why Cardiac Malformations are Correct:** Lithium is a known teratogen, particularly when administered during the first trimester of pregnancy. While the absolute risk is lower than previously thought, the most common category of anomalies associated with lithium use is **cardiac malformations**. Specifically, lithium is classically associated with **Ebstein’s Anomaly**, a rare defect characterized by the downward displacement of the tricuspid valve into the right ventricle ("atrialization" of the ventricle). While Ebstein’s is the most *specific* association, general cardiac septal defects are numerically more common in lithium-exposed infants. **2. Why the Other Options are Incorrect:** * **B. Neural Tube Defects:** These (e.g., spina bifida) are primarily associated with **Valproate** and **Carbamazepine** due to their interference with folate metabolism. * **C. Renal Anomaly:** While lithium causes renal side effects in adults (like Nephrogenic Diabetes Insipidus), it is not the primary congenital concern. However, "Floppy Baby Syndrome" and neonatal hypothyroidism can occur if lithium is used near term. * **D. Fetal Hydantoin Syndrome:** This is a specific constellation of defects (cranial-facial abnormalities, hypoplastic nails/digits) caused by maternal use of **Phenytoin**. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Ratio:** The risk of Ebstein’s anomaly in the general population is 1 in 20,000; with lithium exposure, it increases to approximately 1 in 1,000. * **Management:** If a patient on lithium plans to conceive, the drug should ideally be tapered. If pregnancy is discovered, a **fetal echocardiogram** and Level II ultrasound are mandatory at 18–20 weeks. * **Breastfeeding:** Lithium is generally **avoided** during breastfeeding as it is excreted in high concentrations in breast milk, risking lithium toxicity in the neonate.

Practice by Chapter

Principles of Psychopharmacology

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Antipsychotic Medications

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Antidepressant Medications

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Mood Stabilizers

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Anxiolytics and Hypnotics

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Stimulants and Cognitive Enhancers

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Pharmacokinetics and Pharmacodynamics

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Drug Interactions

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Adverse Effects and Management

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Pharmacogenomics in Psychiatry

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Special Populations Considerations

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Treatment Algorithms and Guidelines

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