Psychopharmacology — MCQs

Psychopharmacology Indian Medical PG Practice Questions and MCQs

Question 91: Which mood stabilizer is used in the management of temporal lobe epilepsy?

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

Explanation: **Explanation:** **Carbamazepine** is the drug of choice for the management of **Temporal Lobe Epilepsy (TLE)**, also known as focal seizures with impaired awareness. While it is primarily an anticonvulsant, it is a potent mood stabilizer used in Psychiatry for the treatment of Acute Mania and Prophylaxis of Bipolar Disorder, especially in patients who are non-responsive to Lithium. Its mechanism involves blocking voltage-gated sodium channels, which stabilizes hyperexcitable neuronal membranes. **Analysis of Options:** * **Valproate (Option B):** While Valproate is a broad-spectrum antiepileptic and a first-line mood stabilizer, it is typically the drug of choice for generalized tonic-clonic seizures and myoclonic seizures rather than specifically for TLE. * **Lamotrigine (Option C):** This is used primarily for the maintenance phase of Bipolar Disorder (preventing depressive episodes) and focal seizures. However, it is not the traditional "gold standard" for TLE compared to Carbamazepine. * **Lithium (Option D):** Lithium is the "gold standard" for Bipolar Affective Disorder (BPAD) but has **no anticonvulsant properties**. In fact, Lithium can lower the seizure threshold in high doses. **High-Yield Clinical Pearls for NEET-PG:** * **DOC for TLE:** Carbamazepine. * **Side Effects:** Agranulocytosis, Aplastic anemia, and **Stevens-Johnson Syndrome** (associated with the HLA-B*1502 allele). * **Enzyme Induction:** Carbamazepine is a potent **cytochrome P450 inducer**, leading to many drug-drug interactions (e.g., reducing the efficacy of oral contraceptives). * **SIADH:** It can cause hyponatremia by increasing ADH sensitivity.

Question 92: Which of the following drugs requires serum level monitoring?

A. Lorazepam
B. Lithium (Correct Answer)
C. Amitriptyline
D. Haloperidol

Explanation: **Explanation:** **Lithium** is the correct answer because it has a **narrow therapeutic index**, meaning the difference between a therapeutic dose and a toxic dose is very small. Therapeutic drug monitoring (TDM) is mandatory to ensure efficacy and prevent severe toxicity (nephrotoxicity, neurotoxicity). The standard therapeutic range for maintenance is **0.6 to 1.2 mEq/L**. Levels above 1.5 mEq/L are generally considered toxic. **Why the other options are incorrect:** * **Lorazepam (Benzodiazepine):** These drugs have a wide therapeutic window. Clinical response and side effects (sedation) are monitored clinically rather than through serum levels. * **Amitriptyline (TCA):** While TCAs can be monitored in specific refractory cases, it is not a routine clinical requirement for standard treatment, unlike Lithium. * **Haloperidol (Antipsychotic):** Dosing is guided by clinical improvement of psychotic symptoms and the emergence of extrapyramidal side effects (EPS), not by plasma concentrations. **High-Yield Clinical Pearls for NEET-PG:** * **Sampling Time:** Lithium levels should be drawn **12 hours after the last dose** (Trough level). * **Steady State:** It takes approximately **5 days** (5 half-lives) to reach a steady state before the first level should be checked. * **Monitoring Frequency:** Initially every 1–2 weeks; once stable, every 3–6 months. * **Factors increasing Lithium levels:** Dehydration, low-sodium diet, and drugs like **NSAIDs, Thiazides, and ACE inhibitors** (mnemonic: **NSA**). * **Side Effects:** Ebstein’s anomaly (teratogenic), Nephrogenic Diabetes Insipidus, and Hypothyroidism.

Question 93: Schizophrenia drugs mainly act on which receptors?

A. D1 dopamine receptors
B. D2 dopamine receptors (Correct Answer)
C. D3 dopamine receptors
D. Acetylcholine receptors

Explanation: ### Explanation **Core Concept: The Dopamine Hypothesis** The primary mechanism of action for most antipsychotic medications (both typical and atypical) is the blockade of **D2 dopamine receptors**. The "Dopamine Hypothesis" of schizophrenia suggests that overactivity of dopamine in the **mesolimbic pathway** leads to positive symptoms (hallucinations and delusions). By antagonizing D2 receptors in this pathway, antipsychotics reduce these symptoms. **Analysis of Options:** * **B. D2 dopamine receptors (Correct):** All effective antipsychotics have a high affinity for D2 receptors. Typical antipsychotics (e.g., Haloperidol) are potent D2 antagonists, while Atypical antipsychotics (e.g., Risperidone) combine D2 blockade with 5-HT2A (serotonin) antagonism. * **A. D1 dopamine receptors:** While some drugs (like Clozapine) show binding affinity for D1, it is not the primary target for treating core psychotic symptoms. * **C. D3 dopamine receptors:** These are primarily located in the limbic system. While newer drugs like Cariprazine act on D3, D2 remains the standard pharmacological target for the class. * **D. Acetylcholine receptors:** Antipsychotics do not treat schizophrenia via these receptors. In fact, blocking acetylcholine receptors (anticholinergic effect) is a common *side effect* of low-potency antipsychotics (e.g., Chlorpromazine). **High-Yield Clinical Pearls for NEET-PG:** 1. **Threshold for Effect:** To achieve an antipsychotic effect, approximately **60-70%** of D2 receptors must be blocked. 2. **Extrapyramidal Symptoms (EPS):** If D2 blockade in the **nigrostriatal pathway** exceeds **80%**, patients develop EPS (Parkinsonism, Akathisia). 3. **Hyperprolactinemia:** D2 blockade in the **tuberoinfundibular pathway** leads to increased prolactin levels. 4. **Clozapine Exception:** Clozapine is the "gold standard" for treatment-resistant schizophrenia; it has a relatively low affinity for D2 but high affinity for D4 and 5-HT2A receptors.

Question 94: Who introduced the antipsychotic chlorpromazine?

A. Delay and Deniker (Correct Answer)
B. John F. Cade
C. Maslow
D. Erik Erikson

Explanation: **Explanation:** **Chlorpromazine**, the first typical antipsychotic, revolutionized psychiatry by shifting treatment from custodial care to pharmacological management. It was synthesized in 1950 by Paul Charpentier as an antihistamine. However, its profound antipsychotic properties were first recognized and introduced into clinical psychiatry in **1952** by the French psychiatrists **Jean Delay and Pierre Deniker**. They observed its "neuroleptic" effect—specifically its ability to reduce agitation and psychosis without inducing profound sedation. **Analysis of Incorrect Options:** * **John F. Cade:** An Australian psychiatrist who discovered the mood-stabilizing effects of **Lithium** in 1948 for the treatment of mania. * **Abraham Maslow:** A psychologist famous for proposing the **Hierarchy of Needs**, a theory of psychological health predicated on fulfilling innate human needs in priority. * **Erik Erikson:** A developmental psychologist known for his theory on the **Eight Stages of Psychosocial Development** (e.g., Trust vs. Mistrust). **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism of Action:** Chlorpromazine is a low-potency antipsychotic that primarily acts by blocking **D2 receptors** in the mesolimbic pathway. * **Side Effects:** Due to its low potency, it has a high affinity for H1 (sedation), Alpha-1 (orthostatic hypotension), and M1 (anticholinergic effects) receptors. * **Specific Side Effect:** It is classically associated with **pigmentary deposits** in the lens and cornea (unlike Thioridazine, which causes retinal deposits). * **Historical Note:** It was initially used by Henri Laborit to prevent surgical shock (the "lytic cocktail").

Question 95: What is the drug of choice for Akathisia?

A. Dantrolene sodium
B. Propranolol (Correct Answer)
C. Anticholinergics
D. Levodopa

Explanation: ### Explanation **Correct Answer: B. Propranolol** **Mechanism and Rationale:** Akathisia is an Extrapyramidal Side Effect (EPS) characterized by a subjective feeling of inner restlessness and an objective inability to sit still. Unlike other EPS (like dystonia), akathisia often responds poorly to anticholinergics. **Propranolol**, a non-selective beta-blocker, is the **drug of choice**. It works by crossing the blood-brain barrier and antagonizing beta-adrenergic receptors, which modulates the catecholaminergic pathways involved in motor restlessness. **Analysis of Incorrect Options:** * **A. Dantrolene sodium:** This is a peripherally acting muscle relaxant used primarily in the management of **Neuroleptic Malignant Syndrome (NMS)** and Malignant Hyperthermia. It has no role in treating akathisia. * **C. Anticholinergics (e.g., Benztropine, Trihexyphenidyl):** These are the drugs of choice for **Acute Dystonia** and Drug-Induced Parkinsonism. While sometimes used for akathisia, they are significantly less effective than beta-blockers. * **D. Levodopa:** This is used in Parkinson’s disease. In psychiatry, dopamine agonists are generally avoided as they can exacerbate psychotic symptoms. **High-Yield Clinical Pearls for NEET-PG:** 1. **Clinical Presentation:** Patients often describe "jumping out of their skin" or constant pacing. It is the most common EPS associated with second-generation antipsychotics (especially Aripiprazole). 2. **Management Hierarchy:** First, reduce the dose of the antipsychotic. If not possible, start **Propranolol** (typical dose: 30–90 mg/day). Second-line agents include Benzodiazepines (e.g., Lorazepam). 3. **Suicide Risk:** Akathisia is uniquely associated with an increased risk of agitation and **suicidality**; therefore, prompt treatment is critical.

Question 96: Lithium is the treatment of choice for which condition?

A. Unipolar major depressive disorder prophylaxis
B. Bipolar major depressive disorder prophylaxis (Correct Answer)
C. Schizophrenia
D. Acute mania

Explanation: **Explanation:** **Lithium** is a monovalent cation and the gold-standard mood stabilizer in psychiatry. While it has multiple applications, its most definitive role is in the **long-term prophylaxis of Bipolar Disorder**, where it effectively prevents the recurrence of both manic and depressive episodes. **Why Option B is Correct:** Lithium is the **treatment of choice (TOC) for the prophylaxis of Bipolar Affective Disorder (BPAD)**. It significantly reduces the frequency, severity, and duration of future episodes. It is particularly superior in preventing manic relapses but is also highly effective in preventing bipolar depression. **Analysis of Incorrect Options:** * **Option A (Unipolar MDD Prophylaxis):** SSRIs or other antidepressants are the first-line maintenance therapy for recurrent unipolar depression. Lithium is only used here as an **augmentation strategy** for treatment-resistant cases. * **Option C (Schizophrenia):** Antipsychotics (e.g., Risperidone, Olanzapine) are the mainstay. Lithium has no role in treating core schizophrenia symptoms unless there is a significant affective component (Schizoaffective disorder). * **Option D (Acute Mania):** While Lithium is used in acute mania, it has a **slow onset of action** (5–7 days). Therefore, in clinical practice, **Valproate** or atypical antipsychotics are often preferred for rapid control, or used in combination with Lithium. **High-Yield NEET-PG Pearls:** * **Therapeutic Index:** Narrow (0.6–1.2 mEq/L). Toxicity occurs >1.5 mEq/L. * **Anti-suicidal Property:** Lithium and Clozapine are the only psychiatric drugs proven to reduce the risk of suicide. * **Teratogenicity:** Causes **Ebstein’s Anomaly** (tricuspid valve displacement) if taken during the first trimester. * **Monitoring:** Before starting, check **Thyroid Function Tests (TFT)** and **Renal Function Tests (RFT)**, as it can cause nephrogenic diabetes insipidus and hypothyroidism.

Question 97: Which of the following is NOT used in the treatment for tardive dyskinesia?

A. Clozapine
B. Vitamin E
C. Clonazepam
D. Haloperidol (Correct Answer)

Explanation: **Explanation:** **Tardive Dyskinesia (TD)** is a delayed-onset extrapyramidal side effect caused by the long-term use of dopamine receptor blockers (typically first-generation antipsychotics). It is characterized by involuntary, choreoathetoid movements, most commonly involving the tongue, face, and jaw (orofacial dyskinesia). **Why Haloperidol is the correct answer:** Haloperidol is a high-potency, first-generation antipsychotic and a potent **D2 receptor antagonist**. Since TD is pathophysiologically linked to **dopamine receptor supersensitivity** resulting from chronic blockade, administering more Haloperidol may temporarily mask the symptoms but will ultimately worsen the underlying condition and increase the risk of irreversible damage. Therefore, it is contraindicated as a treatment for TD. **Analysis of incorrect options:** * **Clozapine (Option A):** This is the drug of choice for patients with TD who still require antipsychotic therapy. It has low D2 affinity and may even help suppress existing dyskinetic movements. * **Vitamin E (Option B):** Used as an antioxidant to prevent further neuronal damage. While its efficacy is modest, it is a recognized adjunct in early-stage TD management. * **Clonazepam (Option C):** Benzodiazepines can be used as an adjunctive treatment to reduce the severity of movements through GABAergic modulation. **NEET-PG High-Yield Pearls:** * **First-line treatment:** Discontinue the offending agent or switch to Clozapine/Quetiapine. * **FDA-approved treatments:** VMAT-2 inhibitors (**Valbenazine** and **Deutetrabenazine**) are now considered the gold standard for TD management. * **Risk Factors:** Old age, female gender, and presence of affective disorders. * **Important Note:** Unlike acute dystonia, **anticholinergics (like Benztropine) worsen TD** and should be avoided.

Question 98: Which of the following pharmacologic agents has the highest potential to cause metabolic syndrome?

A. Clozapine (Correct Answer)
B. Risperidone
C. Quetiapine
D. Aripiprazole

Explanation: **Explanation:** The risk of **Metabolic Syndrome** (weight gain, dyslipidemia, and hyperglycemia/Type 2 Diabetes) is a significant side effect of Second-Generation Antipsychotics (SGAs). This is primarily due to their antagonistic action at **H1 (histamine)** and **5-HT2C (serotonin)** receptors, which increases appetite and disrupts insulin sensitivity. **Why Clozapine is Correct:** Among all antipsychotics, **Clozapine** and **Olanzapine** carry the **highest risk** for metabolic syndrome. Clozapine causes profound weight gain and has a direct effect on insulin resistance, often independent of weight gain. Because of this, patients on Clozapine require mandatory monitoring of BMI, waist circumference, fasting blood glucose, and lipid profiles. **Analysis of Incorrect Options:** * **Risperidone:** Carries a **moderate risk**. While it is associated with weight gain and significant prolactin elevation, its metabolic impact is less severe than Clozapine or Olanzapine. * **Quetiapine:** Also carries a **moderate risk**. It is more metabolically offending than Risperidone but generally less so than Clozapine. * **Aripiprazole:** This is a **metabolically neutral** drug (along with Ziprasidone and Lurasidone). As a partial D2 agonist, it has a very low potential for weight gain or glucose dysregulation. **High-Yield NEET-PG Pearls:** * **Highest Metabolic Risk:** Clozapine > Olanzapine. * **Lowest Metabolic Risk:** Aripiprazole, Ziprasidone, Lurasidone. * **Clozapine Monitoring:** Apart from metabolic parameters, remember the mandatory **ANC (Absolute Neutrophil Count)** monitoring due to the risk of **Agranulocytosis**. * **Drug of Choice:** Clozapine remains the gold standard for **Treatment-Resistant Schizophrenia**.

Question 99: Which of the following is the drug of choice for medication-resistant schizophrenia?

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

Explanation: **Explanation:** **Clozapine** is the gold-standard treatment and the **drug of choice for treatment-resistant schizophrenia (TRS)**. TRS is clinically defined as schizophrenia that fails to respond to adequate trials (at least 4–6 weeks) of at least two different antipsychotics at therapeutic doses. Clozapine is a Dibenzodiazepine derivative and an "atypical" (second-generation) antipsychotic. Its superior efficacy is attributed to its unique receptor profile, characterized by a high affinity for D4 and 5-HT2A receptors and a relatively low affinity for D2 receptors. It is also the only antipsychotic proven to reduce suicidal behavior in schizophrenic patients. **Why the other options are incorrect:** * **Haloperidol (A) & Chlorpromazine (B):** These are first-generation (typical) antipsychotics. While effective for positive symptoms, they are not indicated for resistant cases and carry a high risk of Extrapyramidal Side Effects (EPS) and Tardive Dyskinesia. * **Flupentixol (D):** A thioxanthene derivative often used as a long-acting injectable (depot). While useful for maintenance and compliance, it has no specific role in medication-resistant schizophrenia. **High-Yield Clinical Pearls for NEET-PG:** * **Agranulocytosis:** The most dreaded side effect of Clozapine (occurs in ~1%). Mandatory **Absolute Neutrophil Count (ANC)** monitoring is required. * **Seizures:** Clozapine significantly lowers the seizure threshold in a dose-dependent manner. * **Sialorrhea:** Paradoxical hypersalivation (especially at night) is a common, bothersome side effect. * **Metabolic Syndrome:** Clozapine carries the highest risk of weight gain and diabetes among antipsychotics. * **No EPS:** Clozapine has the lowest risk of Extrapyramidal Side Effects and does not cause Tardive Dyskinesia.

Question 100: Which of the following medications is NOT used for schizophrenia?

A. Chlorpromazine
B. Clozapine
C. Risperidone
D. Venlafaxine (Correct Answer)

Explanation: **Explanation:** The correct answer is **Venlafaxine** because it is a **Serotonin-Norepinephrine Reuptake Inhibitor (SNRI)**, primarily used as an antidepressant and for anxiety disorders. It does not possess the dopamine (D2) receptor antagonism required to treat the core psychotic symptoms of schizophrenia. **Analysis of Options:** * **Chlorpromazine (Option A):** A prototypical **Typical (First-generation) Antipsychotic**. It works by blocking D2 receptors in the mesolimbic pathway. It is also known for its low potency and side effects like sedation and orthostatic hypotension. * **Clozapine (Option B):** An **Atypical (Second-generation) Antipsychotic**. It is the "gold standard" for **treatment-resistant schizophrenia**. It has a unique profile with high affinity for D4 and 5-HT2 receptors but carries a risk of agranulocytosis. * **Risperidone (Option C):** A commonly used **Atypical Antipsychotic**. It blocks both D2 and 5-HT2A receptors. It is notable for having a higher risk of extrapyramidal symptoms (EPS) and hyperprolactinemia compared to other atypicals at higher doses. **High-Yield Clinical Pearls for NEET-PG:** * **Dopamine Hypothesis:** Schizophrenia is primarily linked to overactivity of dopamine in the mesolimbic pathway (positive symptoms) and underactivity in the mesocortical pathway (negative symptoms). * **Clozapine Monitoring:** Requires mandatory WBC and ANC monitoring due to the risk of **agranulocytosis** (occurs in ~1%). It is also the only antipsychotic proven to reduce suicide risk in schizophrenia. * **Drug of Choice:** For a first episode of schizophrenia, atypical antipsychotics (like Risperidone or Olanzapine) are generally preferred over typicals due to a lower risk of tardive dyskinesia.

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

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