Psychopharmacology — MCQs

Psychopharmacology Indian Medical PG Practice Questions and MCQs

Question 71: Which of the following is true about psychoactive drugs?

A. Can cause sexual dysfunction
B. Used in OCD
C. Used in psychotic disorders and drug withdrawal
D. All of the above (Correct Answer)

Explanation: **Explanation:** Psychoactive drugs (psychotropics) are substances that cross the blood-brain barrier to affect the neurochemistry of the Central Nervous System (CNS), thereby altering perception, mood, consciousness, and behavior. * **Option A (Sexual Dysfunction):** This is a very common side effect of several psychotropic classes. Most notably, **SSRIs** (Selective Serotonin Reuptake Inhibitors) frequently cause decreased libido and delayed ejaculation due to increased serotonergic tone. Antipsychotics can also cause sexual dysfunction via **hyperprolactinemia** (due to Dopamine D2 blockade in the tuberoinfundibular pathway). * **Option B (Used in OCD):** Obsessive-Compulsive Disorder is primarily treated with high-dose SSRIs (e.g., Fluoxetine, Fluvoxamine) or the TCA **Clomipramine** (the gold standard, though second-line due to side effects). * **Option C (Used in Psychotic Disorders and Drug Withdrawal):** Antipsychotics (e.g., Haloperidol, Risperidone) are the mainstay for schizophrenia and bipolar mania. Additionally, psychoactive drugs like **Benzodiazepines** are the treatment of choice for alcohol withdrawal, while **Methadone or Buprenorphine** are used for opioid withdrawal. Since all statements accurately describe the clinical profile and utility of psychoactive drugs, **Option D** is the correct answer. **NEET-PG High-Yield Pearls:** * **Drug of Choice for OCD:** SSRIs (First-line); Clomipramine (Most potent). * **Sexual Dysfunction:** Bupropion and Mirtazapine are the preferred antidepressants if a patient experiences significant sexual side effects. * **Withdrawal:** Chlordiazepoxide is frequently used for detoxification in alcohol dependence syndrome.

Question 72: A 40-year-old male presents with poor adherence to Haloperidol 10mg BD. He complains of unpleasant motor symptoms and reports having an 'urge to move' constantly. His wife reports that he is restless all the time. Which of the following explains the symptoms?

A. Tourette's Syndrome
B. Hyperkinetic Disorder
C. Akathisia (Correct Answer)
D. Psychotic Agitation

Explanation: ### Explanation **Correct Answer: C. Akathisia** **Why it is correct:** Akathisia is a common **Extrapyramidal Side Effect (EPS)** caused by high-potency first-generation antipsychotics like Haloperidol. It is characterized by a subjective feeling of inner restlessness and an objective compulsion to move. The patient’s description of an "urge to move" and the wife’s observation of constant restlessness are classic clinical presentations. Pathophysiologically, it results from **dopamine (D2) receptor blockade** in the nigrostriatal pathway. **Why the other options are incorrect:** * **A. Tourette’s Syndrome:** This is a neurodevelopmental disorder characterized by multiple motor and at least one vocal tic lasting >1 year. It typically starts in childhood, not as a side effect of medication in a 40-year-old. * **B. Hyperkinetic Disorder (ADHD):** This involves a persistent pattern of inattention and/or hyperactivity-impulsivity. While it involves restlessness, it is a chronic developmental condition, not an acute drug-induced state. * **C. Psychotic Agitation:** While psychosis can cause agitation, it is usually driven by delusions or hallucinations. In this case, the symptoms are specifically described as "motor symptoms" following Haloperidol use, pointing toward a side effect rather than the primary illness. **NEET-PG High-Yield Pearls:** * **Management:** The first-line treatment for Akathisia is **Propranolol** (Beta-blocker). Benzodiazepines or anticholinergics (like Benztropine) can be used as second-line. * **Timeline:** Akathisia typically develops within days to weeks of starting or increasing the dose of an antipsychotic. * **Clinical Sign:** Patients are often seen pacing, shifting weight from foot to foot, or inability to sit still ("Mal de la marche"). * **Risk:** Akathisia is a major cause of **non-adherence** to treatment and is associated with an increased risk of suicide due to the extreme distress it causes.

Question 73: What is the drug of choice for bipolar mood disorder?

A. Carbamazepine
B. Lithium carbonate (Correct Answer)
C. Imipramine
D. Buspirone

Explanation: **Explanation:** **Lithium carbonate** remains the gold standard and the **drug of choice (DOC)** for the treatment of Bipolar Mood Disorder (BMD). It is unique because it is effective in treating acute mania, preventing future manic and depressive relapses (prophylaxis), and is the only psychiatric medication proven to significantly **reduce the risk of suicide** in these patients. Its mechanism involves the inhibition of the inositol monophosphatase pathway and modulation of G-proteins. **Analysis of Incorrect Options:** * **Carbamazepine (Option A):** While used as a mood stabilizer, it is generally considered a second-line agent. It is preferred in cases of "Rapid Cycling" BMD or when patients do not respond to Lithium. * **Imipramine (Option C):** This is a Tricyclic Antidepressant (TCA). Using antidepressants alone in BMD is risky as they can precipitate a "switch" into acute mania. * **Buspirone (Option D):** This is a non-benzodiazepine anxiolytic used primarily for Generalized Anxiety Disorder (GAD). It has no role in the stabilization of mood in BMD. **High-Yield Clinical Pearls for NEET-PG:** * **Therapeutic Index:** Lithium has a narrow therapeutic index. Monitoring serum levels is essential (Target: **0.8–1.2 mEq/L** for acute mania; **0.6–0.8 mEq/L** for maintenance). * **Teratogenicity:** Use in pregnancy is associated with **Ebstein’s Anomaly** (atrialization of the right ventricle). * **Side Effects:** Common boards-favorite side effects include fine tremors, hypothyroidism, and Nephrogenic Diabetes Insipidus. * **Drug Interactions:** Thiazides, NSAIDs, and ACE inhibitors can increase Lithium levels, leading to toxicity.

Question 74: Which of the following antipsychotic drugs are available as an injectable depot preparation?

A. Aripiprazole
B. Fluphenazine (Correct Answer)
C. Trifluoperazine
D. Ziprasidone

Explanation: **Explanation:** **Depot antipsychotics** are long-acting injectable (LAI) formulations used primarily to improve treatment adherence in patients with chronic schizophrenia. These medications are esterified with long-chain fatty acids (like decanoate or enanthate) in an oil vehicle, allowing for slow release over 2–4 weeks. **1. Why Fluphenazine is Correct:** **Fluphenazine decanoate** is a classic high-potency typical antipsychotic available as a depot injection. It is one of the most frequently tested depot preparations in exams, alongside **Haloperidol decanoate**. These are administered intramuscularly and provide stable plasma concentrations for extended periods. **2. Analysis of Incorrect Options:** * **Trifluoperazine (Option C):** While it is a high-potency typical antipsychotic similar to Fluphenazine, it is **not** available in a depot formulation. It is primarily administered orally. * **Ziprasidone (Option D):** This atypical antipsychotic is available as an immediate-release (short-acting) injection for acute agitation, but it does **not** have a long-acting depot form. * **Aripiprazole (Option B):** *Note for NEET-PG:* While Aripiprazole **does** have a long-acting injectable form (Aripiprazole Maintena/Lauroxil), in the context of standard textbook questions and traditional MCQ patterns, **Fluphenazine** remains the classic, definitive answer for "typical" depot preparations. If both are present, Fluphenazine is the historical gold standard for this question type. **High-Yield Clinical Pearls for NEET-PG:** * **Common Depot Drugs:** Fluphenazine decanoate, Haloperidol decanoate, Risperidone microspheres, Paliperidone palmitate, and Zuclopenthixol. * **Injection Site:** Usually the gluteal or deltoid muscle (Z-track technique is often used). * **Test Dose:** Always administer an oral challenge or a small test dose first to check for hypersensitivity or severe Extrapyramidal Side Effects (EPS) before giving a long-acting dose. * **Indication:** Poor compliance/adherence is the #1 indication for switching to a depot.

Question 75: Which recently approved NMDA blocker is used for the management of treatment-resistant depression in adults?

A. Esketamine (Correct Answer)
B. Siponimod
C. Erdafitinib
D. Risankizumab

Explanation: **Explanation:** **Esketamine** is the correct answer. It is the S-enantiomer of ketamine and acts as a non-competitive **N-methyl-D-aspartate (NMDA) receptor antagonist**. In 2019, the FDA approved Esketamine (nasal spray) for **Treatment-Resistant Depression (TRD)** in adults, defined as patients who have not responded to at least two antidepressant treatments of adequate dose and duration. Unlike traditional antidepressants that target monoamines (Serotonin/Norepinephrine) and take weeks to work, Esketamine modulates glutamate neurotransmission, providing rapid-acting antidepressant effects. **Analysis of Incorrect Options:** * **Siponimod (B):** A sphingosine-1-phosphate (S1P) receptor modulator used for the treatment of secondary progressive multiple sclerosis (SPMS). * **Erdafitinib (C):** A fibroblast growth factor receptor (FGFR) kinase inhibitor used in the treatment of metastatic urothelial carcinoma. * **Risankizumab (D):** An interleukin-23 (IL-23) inhibitor used for plaque psoriasis, psoriatic arthritis, and Crohn’s disease. **High-Yield Clinical Pearls for NEET-PG:** * **Administration:** Esketamine is administered as a **nasal spray** under direct medical supervision due to risks of sedation and dissociation. * **Monitoring:** Patients must be monitored for at least **2 hours** post-administration for blood pressure spikes and "out-of-body" experiences (dissociation). * **Mechanism:** It increases the expression of **BDNF** (Brain-Derived Neurotrophic Factor) and enhances synaptic plasticity. * **Ketamine vs. Esketamine:** While both are NMDA blockers, Esketamine has a higher affinity for the NMDA receptor, allowing for lower dosing.

Question 76: Which of the following drugs is preferred for the management of depression associated with insomnia?

A. Mianserin (Correct Answer)
B. Venlafaxine
C. Sertraline
D. Desipramine

Explanation: **Explanation:** The correct answer is **Mianserin**. **1. Why Mianserin is correct:** Mianserin is a tetracyclic antidepressant (TeCA) that acts as a potent antagonist at **H1 (histamine)** and **5-HT2** receptors. Its strong antihistaminic property provides a significant **sedative effect**, making it highly effective for depressed patients suffering from prominent insomnia. Unlike many other antidepressants, it lacks significant anticholinergic side effects, which often makes it better tolerated in specific populations. **2. Why the other options are incorrect:** * **Venlafaxine (SNRI):** This drug increases norepinephrine and serotonin levels. It is generally considered **activating** and can actually cause or worsen insomnia as a side effect. * **Sertraline (SSRI):** Like most SSRIs, sertraline is more likely to cause insomnia, restlessness, or agitation, especially during the initial phase of treatment. It is typically administered in the morning. * **Desipramine (TCA):** While some TCAs are sedative (like Amitriptyline), Desipramine is a secondary amine that primarily inhibits norepinephrine reuptake. It is one of the **least sedating** TCAs and can sometimes be stimulating. **3. NEET-PG High-Yield Pearls:** * **Mirtazapine** (a related NaSSA) is also a high-yield answer for depression with insomnia/weight loss due to its H1 antagonism and weight-gain profile. * **Trazodone** is another antidepressant frequently used "off-label" at low doses specifically for its hypnotic properties. * **Mechanism of Mianserin:** It blocks alpha-2 adrenergic receptors (increasing NE release) and 5-HT2, 5-HT3, and H1 receptors. * **Side Effect Note:** Mianserin is associated with a rare risk of **agranulocytosis**; therefore, monitoring of CBC is sometimes recommended.

Question 77: What is the drug of choice for rapid cyclers in manic–depressive psychosis?

A. Carbamazepine
B. Valproate (Correct Answer)
C. Phenytoin
D. Lithium

Explanation: **Explanation:** **1. Why Valproate is the Correct Answer:** Rapid cycling Bipolar Disorder is defined as having **four or more mood episodes** (manic, hypomanic, or depressive) within a 12-month period. Clinical studies and guidelines (such as CANMAT) establish **Valproate (Sodium Valproate/Divalproex)** as the drug of choice for rapid cyclers. It is more effective than Lithium in these patients because rapid cycling is often associated with mixed features and comorbid substance abuse, scenarios where Valproate shows superior efficacy in stabilizing mood and reducing the frequency of episodes. **2. Why the Other Options are Incorrect:** * **Lithium (Option D):** While Lithium is the "Gold Standard" for classic Bipolar I (euphoric mania), it is notoriously **less effective** in rapid cyclers and mixed states. Patients with rapid cycling often show a poor prophylactic response to Lithium. * **Carbamazepine (Option A):** This is considered a second-line mood stabilizer. While it can be used in rapid cycling if Valproate fails, it is not the first-line "drug of choice" due to its side effect profile and enzyme-inducing properties. * **Phenytoin (Option C):** This is an antiepileptic medication with no proven efficacy as a mood stabilizer in psychiatric practice. **3. High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC) for Classic Mania:** Lithium. * **DOC for Rapid Cyclers/Mixed Mania:** Valproate. * **DOC for Bipolar Depression:** Quetiapine, Lurasidone, or Lamotrigine. * **Lithium Monitoring:** Therapeutic range is 0.8–1.2 mEq/L for acute mania and 0.6–1.0 mEq/L for maintenance. * **Valproate Side Effects:** Hepatotoxicity, Pancreatitis, and Neural Tube Defects (Polycystic Ovarian Syndrome is also a common association in females).

Question 78: Which of the following is a side effect of vagal nerve stimulation?

A. Paradoxical suicide
B. Voice alteration (Correct Answer)
C. Arrhythmia
D. Epilepsy

Explanation: **Explanation:** **Vagus Nerve Stimulation (VNS)** is an FDA-approved neuromodulation technique used for treatment-resistant depression and refractory epilepsy. It involves a surgically implanted device that sends electrical pulses to the left vagus nerve. **Why Voice Alteration is Correct:** The vagus nerve (Cranial Nerve X) provides motor innervation to the muscles of the larynx via the **recurrent laryngeal nerve**. During the "on-cycle" of the electrical stimulation, the laryngeal muscles are affected, leading to the most common side effect: **voice alteration or hoarseness**. Other common stimulation-related side effects include cough, throat tickling, and mild dyspnea. **Analysis of Incorrect Options:** * **A. Paradoxical suicide:** While antidepressants carry a black-box warning for increased suicidal ideation in young adults, VNS is actually associated with a long-term *reduction* in suicidal ideation in treatment-resistant patients. * **C. Arrhythmia:** Although the vagus nerve influences heart rate, VNS is typically performed on the **left** vagus nerve because the right vagus nerve has a more significant innervation of the sinoatrial (SA) node. Stimulating the left side minimizes the risk of bradycardia or arrhythmias. * **D. Epilepsy:** VNS is a **treatment** for epilepsy, not a cause. It is used to reduce the frequency of seizures in patients who do not respond to anti-epileptic drugs. **High-Yield Clinical Pearls for NEET-PG:** * **Indication:** Treatment-resistant depression (failed 4+ adequate antidepressant trials). * **Site:** The pulse generator is usually implanted in the left chest wall, and electrodes are wrapped around the **left** vagus nerve. * **Side Effect Profile:** Most side effects are "stimulus-dependent," meaning they only occur when the device is actively pulsing. * **Contraindication:** VNS is contraindicated in patients with bilateral or left cervical vagotomy.

Question 79: Which of the following antidepressants is a reversible inhibitor of monoamine oxidase A (RIMA)?

A. Moclobemide (Correct Answer)
B. Phenelzine
C. Sertraline
D. Fluoxetine

Explanation: **Explanation:** **Moclobemide** is the correct answer because it belongs to the class of **Reversible Inhibitors of Monoamine Oxidase A (RIMA)**. Unlike older, irreversible MAOIs, Moclobemide selectively inhibits the MAO-A enzyme (which metabolizes serotonin, norepinephrine, and dopamine) in a reversible manner. This reversibility is clinically significant because if systemic tyramine levels rise (e.g., from consuming aged cheese), the tyramine can displace Moclobemide from the enzyme, allowing for tyramine metabolism and significantly reducing the risk of a hypertensive crisis ("cheese reaction"). **Analysis of Incorrect Options:** * **Phenelzine:** This is a **non-selective, irreversible MAO inhibitor**. It binds permanently to both MAO-A and MAO-B, requiring strict dietary restrictions to avoid life-threatening hypertensive crises. * **Sertraline & Fluoxetine:** These are **Selective Serotonin Reuptake Inhibitors (SSRIs)**. They work by inhibiting the serotonin transporter (SERT) rather than the MAO enzyme. Fluoxetine is notable for its very long half-life due to its active metabolite, norfluoxetine. **High-Yield Clinical Pearls for NEET-PG:** * **The "Cheese Reaction":** Occurs when tyramine displaces stored norepinephrine; RIMAs like Moclobemide have a much lower risk compared to Phenelzine or Tranylcypromine. * **MAO-B Inhibitor:** **Selegiline** (used in Parkinson’s) is a selective MAO-B inhibitor at low doses but loses selectivity at higher antidepressant doses. * **Washout Period:** When switching from an MAOI to an SSRI, a 2-week washout period is required (5 weeks for Fluoxetine) to prevent **Serotonin Syndrome**. * **Drug of Choice:** SSRIs (like Sertraline) remain the first-line treatment for depression due to their superior safety profile.

Question 80: What is the drug of choice for the treatment of negative symptoms of schizophrenia?

A. Chlorpromazine
B. Haloperidol
C. Clozapine (Correct Answer)
D. Doxepin

Explanation: **Explanation:** The treatment of schizophrenia involves addressing both **positive symptoms** (hallucinations, delusions) and **negative symptoms** (apathy, anhedonia, social withdrawal, alogia). **Why Clozapine is the Correct Answer:** Clozapine is an **Atypical Antipsychotic (Second-Generation Antipsychotic)**. Unlike typical antipsychotics that primarily block $D_2$ receptors, atypical agents like Clozapine have a high affinity for **$5-HT_{2A}$ receptors** and a relatively lower affinity for $D_2$ receptors. This serotonin-dopamine antagonism in the mesocortical pathway is believed to improve negative symptoms and cognitive deficits. Clozapine is specifically indicated for **treatment-resistant schizophrenia** and is considered the most effective drug for reducing negative symptoms. **Analysis of Incorrect Options:** * **A & B (Chlorpromazine & Haloperidol):** These are **Typical Antipsychotics (First-Generation)**. They act via potent $D_2$ blockade in the mesolimbic pathway. While effective for positive symptoms, they are largely ineffective for negative symptoms and may even worsen them by causing "secondary negative symptoms" due to extrapyramidal side effects (EPS). * **D (Doxepin):** This is a **Tricyclic Antidepressant (TCA)**. It has no role in the primary treatment of schizophrenia or its negative symptoms. **High-Yield Clinical Pearls for NEET-PG:** * **Clozapine Side Effects:** Agranulocytosis (requires mandatory WBC monitoring), seizures (dose-dependent), myocarditis, and significant weight gain/metabolic syndrome. * **DOC for Treatment-Resistant Schizophrenia:** Clozapine (defined as failure of 2 adequate trials of other antipsychotics). * **Suicide Prevention:** Clozapine is the only antipsychotic FDA-approved to reduce the risk of suicidal behavior in schizophrenia. * **Negative Symptoms:** Often associated with decreased dopaminergic activity in the **mesocortical pathway**.

Practice by Chapter

Principles of Psychopharmacology

Practice Questions

Antipsychotic Medications

Practice Questions

Antidepressant Medications

Practice Questions

Mood Stabilizers

Practice Questions

Anxiolytics and Hypnotics

Practice Questions

Stimulants and Cognitive Enhancers

Practice Questions

Pharmacokinetics and Pharmacodynamics

Practice Questions

Drug Interactions

Practice Questions

Adverse Effects and Management

Practice Questions

Pharmacogenomics in Psychiatry

Practice Questions

Special Populations Considerations

Practice Questions

Treatment Algorithms and Guidelines

Practice Questions

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