Psychopharmacology — MCQs
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Irresistible urge to move about with inner restlessness is called?
Which of the following adverse effects may be seen in a patient treated with risperidone?
A 30-year-old man, recently started on haloperidol 30mg/day, developed hyperpyrexia, muscle rigidity, akinesia, mutism, sweating, tachycardia, and increased blood pressure. Investigations showed increased WBC count and increased creatinine phosphokinase. There is no history of any other drug intake or any signs of infection. What is the most likely diagnosis?
Retrograde ejaculation is a characteristic side effect of which psychotropic medication?
All of the following are used in the treatment of bipolar disorder except?
Which antipsychotic medication is known to cause agranulocytosis?
Which class of drugs is chiefly used for treating schizophrenia?
A 31-year-old male with a mood disorder, on 30 mg of haloperidol and 100 mg of lithium, presents to the emergency room with acute onset of fever, excessive sweating, confusion, limb rigidity, and decreased communication for one day. Examination reveals tachycardia and labile blood pressure. Investigations show increased CPK enzyme levels and leucocytosis. What is the most likely diagnosis?
A 45-year-old male presented to the emergency department with severe agitation and aggressive behavior. He was treated with haloperidol and became responsive and cooperative. After 8 days of treatment, he developed high-grade fever, diarrhea, confusion, and muscle rigidity. Which of the following should be used for the treatment of this condition?
Risperidone is most commonly used to treat which of the following disorders?
Psychopharmacology Indian Medical PG Practice Questions and MCQs
Question 201: Irresistible urge to move about with inner restlessness is called?
- A. Akinesia
- B. Hyperkinesia
- C. Dyskinesia
- D. Akathisia (Correct Answer)
Explanation: ### Explanation **Correct Answer: D. Akathisia** **Akathisia** is a common extrapyramidal side effect (EPS) associated with antipsychotic medications (especially first-generation antipsychotics). It is clinically defined by two components: 1. **Subjective:** A distressing feeling of inner restlessness and anxiety. 2. **Objective:** Motor restlessness, such as pacing, shifting weight from foot to foot, or inability to sit still. The "irresistible urge to move" is the hallmark feature that distinguishes it from simple anxiety or agitation. **Analysis of Incorrect Options:** * **A. Akinesia:** Refers to a lack of or poverty of movement. It is often part of drug-induced parkinsonism, characterized by a "mask-like" face and decreased arm swing. * **B. Hyperkinesia:** A general term for excessive, often involuntary, muscular activity (e.g., tremors, chorea). It lacks the specific "inner restlessness" component of akathisia. * **C. Dyskinesia:** Refers to abnormal, involuntary movements. **Tardive Dyskinesia** is a late-onset EPS characterized by orofacial movements (lip-smacking, tongue protrusion) resulting from long-term dopamine blockade. **High-Yield Clinical Pearls for NEET-PG:** * **Management:** The first-line treatment for Akathisia is **Propranolol** (Beta-blocker). Centrally acting anticholinergics (like Benztropine) or Benzodiazepines can also be used. * **Timeline:** Akathisia typically develops within days to weeks of starting or increasing the dose of an antipsychotic. * **Suicide Risk:** Severe akathisia is highly distressing and has been clinically linked to an increased risk of suicidal ideation and behavior. * **Differential:** Do not confuse Akathisia with **Restless Leg Syndrome (RLS)**; RLS typically occurs at night and is relieved specifically by moving the legs, whereas akathisia is generalized and occurs throughout the day.
Question 202: Which of the following adverse effects may be seen in a patient treated with risperidone?
- A. Weight loss
- B. Neuroleptic malignant syndrome (Correct Answer)
- C. Hypopigmentation
- D. Prolactin deficiency
Explanation: **Explanation:** **Risperidone** is a second-generation (atypical) antipsychotic that acts primarily as a potent **D2 receptor antagonist** and a 5-HT2A receptor antagonist. **Why Option B is Correct:** **Neuroleptic Malignant Syndrome (NMS)** is a rare but life-threatening idiosyncratic reaction to dopamine antagonists, including risperidone. It is characterized by the "tetrad" of **hyperthermia, muscular "lead-pipe" rigidity, autonomic instability, and altered mental status.** The underlying mechanism involves massive dopamine blockade in the nigrostriatal pathway and hypothalamus. **Why Other Options are Incorrect:** * **A. Weight loss:** Risperidone is associated with **weight gain** and metabolic syndrome (dyslipidemia, hyperglycemia), not weight loss. * **C. Hypopigmentation:** Antipsychotics do not cause hypopigmentation. Historically, high-dose Chlorpromazine was associated with *hyperpigmentation* (blue-grey skin discoloration). * **D. Prolactin deficiency:** Risperidone is unique among atypicals for causing significant **Hyperprolactinemia**. By blocking dopamine in the tuberoinfundibular pathway, it removes the inhibitory effect on prolactin, leading to galactorrhea, amenorrhea, and gynecomastia. **High-Yield Clinical Pearls for NEET-PG:** * **NMS Treatment:** Immediate discontinuation of the drug, aggressive cooling, and pharmacotherapy with **Dantrolene** (muscle relaxant) or **Bromocriptine** (dopamine agonist). * **Lab findings in NMS:** Elevated Creatine Kinase (CK) and leukocytosis. * **Risperidone Fact:** It has the highest risk of **Extrapyramidal Side Effects (EPS)** among atypical antipsychotics, especially at doses >6mg.
Question 203: A 30-year-old man, recently started on haloperidol 30mg/day, developed hyperpyrexia, muscle rigidity, akinesia, mutism, sweating, tachycardia, and increased blood pressure. Investigations showed increased WBC count and increased creatinine phosphokinase. There is no history of any other drug intake or any signs of infection. What is the most likely diagnosis?
- A. Drug overdose
- B. Neuroleptic malignant syndrome (Correct Answer)
- C. Drug-induced Parkinsonism
- D. Tardive dyskinesia
Explanation: **Explanation:** The clinical presentation described is a classic case of **Neuroleptic Malignant Syndrome (NMS)**, a life-threatening idiosyncratic reaction to antipsychotic drugs (neuroleptics), particularly high-potency agents like Haloperidol. **Why Option B is Correct:** NMS is characterized by a "tetrad" of clinical features: 1. **Hyperpyrexia:** High-grade fever. 2. **Muscle Rigidity:** Often described as "lead-pipe" rigidity. 3. **Autonomic Instability:** Tachycardia, sweating (diaphoresis), and fluctuating blood pressure. 4. **Altered Mental Status:** Mutism, stupor, or coma. Laboratory findings typically show **elevated Creatinine Phosphokinase (CPK)** due to rhabdomyolysis and **leukocytosis** (increased WBC), both of which are present in this patient. **Why Other Options are Incorrect:** * **A. Drug Overdose:** While Haloperidol overdose can cause sedation or extrapyramidal symptoms, it does not typically present with the specific combination of lead-pipe rigidity, hyperpyrexia, and markedly elevated CPK. * **C. Drug-induced Parkinsonism:** This presents with tremors, bradykinesia, and rigidity, but lacks the life-threatening autonomic instability and hyperpyrexia seen in NMS. * **D. Tardive Dyskinesia:** A late-onset side effect characterized by involuntary choreoathetoid movements (e.g., lip-smacking), not an acute febrile illness. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Massive dopamine blockade in the nigrostriatal pathway and hypothalamus. * **Treatment:** Immediate discontinuation of the antipsychotic, supportive care (cooling), and pharmacotherapy with **Dantrolene** (muscle relaxant) or **Bromocriptine** (D2 agonist). * **Mnemonic (FEVER):** **F**ever, **E**ncephalopathy, **V**itals unstable, **E**levated enzymes (CPK), **R**igidity. * **Differential Diagnosis:** Serotonin Syndrome (presents with hyperreflexia and myoclonus, whereas NMS has "lead-pipe" rigidity and hyporeflexia).
Question 204: Retrograde ejaculation is a characteristic side effect of which psychotropic medication?
- A. Lithium carbonate
- B. Phenelzine
- C. Diazepam
- D. Thioridazine (Correct Answer)
Explanation: **Explanation:** **Thioridazine** is a low-potency typical antipsychotic known for its significant alpha-1 adrenergic blocking properties. Retrograde ejaculation occurs because the closure of the internal urethral sphincter (bladder neck) is mediated by alpha-1 receptors. When these receptors are blocked, the sphincter fails to close during ejaculation, causing semen to travel backward into the bladder instead of out through the urethra. This is a classic, high-yield side effect specifically associated with Thioridazine. **Analysis of Incorrect Options:** * **Lithium carbonate:** Primarily causes side effects like tremors, polyuria (nephrogenic diabetes insipidus), and hypothyroidism. It does not significantly affect the adrenergic system governing ejaculation. * **Phenelzine:** An MAO inhibitor. While it can cause sexual dysfunction (primarily delayed ejaculation or impotence), it is not classically associated with retrograde ejaculation. * **Diazepam:** A benzodiazepine that acts via GABA-A receptors. It may cause decreased libido or erectile dysfunction due to CNS sedation but does not cause the mechanical failure seen in retrograde ejaculation. **Clinical Pearls for NEET-PG:** * **Thioridazine "Mnemonic":** Remember the **"3 Ts"** of Thioridazine: **T**orsades de pointes (QT prolongation), **T**errible Retinitis Pigmentosa (at doses >800mg/day), and **T**ermination of forward ejaculation (Retrograde). * **Mechanism:** Retrograde ejaculation is an **alpha-adrenergic blockade** phenomenon. * **Other drugs:** Apart from Thioridazine, alpha-blockers like **Tamsulosin** (used in BPH) are also common causes of retrograde ejaculation.
Question 205: All of the following are used in the treatment of bipolar disorder except?
- A. Gabapentin (Correct Answer)
- B. Valproate
- C. Lithium
- D. Carbamazepine
Explanation: The treatment of Bipolar Disorder primarily relies on **Mood Stabilizers**. While several anticonvulsants are effective in stabilizing mood, not all drugs in that class possess this property. [1] **Why Gabapentin is the correct answer:** Gabapentin, although an anticonvulsant, has **no proven efficacy as a mood stabilizer** in randomized controlled trials for Bipolar Disorder. It is primarily used for neuropathic pain and as an adjunctive treatment for focal seizures. In psychiatry, it may be used "off-label" for anxiety or alcohol withdrawal, but it is not indicated for the treatment of mania or bipolar depression. [1] **Why the other options are incorrect:** * **Lithium (Option C):** The "Gold Standard" for bipolar disorder. It is highly effective for acute mania and prophylaxis of both manic and depressive episodes. [3] It is also known for its unique anti-suicidal properties. * **Valproate (Option B):** A first-line mood stabilizer, especially effective for **Rapid Cycling** bipolar disorder and Mixed Episodes. [2] * **Carbamazepine (Option D):** A second-line mood stabilizer often used when patients are unresponsive to Lithium or Valproate. [4] It is particularly useful in acute mania. [2] **High-Yield Clinical Pearls for NEET-PG:** * **Drugs of Choice:** Lithium is the overall DOC for Bipolar Disorder; however, Valproate is preferred for Rapid Cyclers (>4 episodes/year). [4] * **Lamotrigine:** Another anticonvulsant used in Bipolar Disorder, but specifically for the **prevention of depressive episodes** (not effective for acute mania). [2] * **Teratogenicity:** Lithium is associated with **Ebstein’s Anomaly**, while Valproate is associated with **Neural Tube Defects** (highest risk among mood stabilizers). * **Topiramate:** Like Gabapentin, Topiramate is an anticonvulsant that is **not** an effective mood stabilizer but is sometimes used for weight loss in psychiatric patients. [1]
Question 206: Which antipsychotic medication is known to cause agranulocytosis?
- A. Lithium
- B. Risperidone
- C. Clozapine (Correct Answer)
- D. Aripiprazole
Explanation: **Explanation:** **Clozapine** is the correct answer. It is an atypical (second-generation) antipsychotic reserved for treatment-resistant schizophrenia. Its most serious and life-threatening side effect is **agranulocytosis** (a severe decrease in the absolute neutrophil count, typically defined as <500/mm³), which occurs in approximately 1% of patients. This reaction is idiosyncratic and usually occurs within the first 18 weeks of treatment. Due to this risk, mandatory hematological monitoring (CBC with ANC) is required for all patients on Clozapine. **Analysis of Incorrect Options:** * **A. Lithium:** This is a mood stabilizer, not an antipsychotic. Interestingly, Lithium causes **leukocytosis** (an increase in white blood cell count) rather than agranulocytosis, and is sometimes used off-label to counteract drug-induced neutropenia. * **B. Risperidone:** An atypical antipsychotic primarily associated with dose-dependent extrapyramidal symptoms (EPS) and significant **hyperprolactinemia**. It does not carry a significant risk of agranulocytosis. * **C. Aripiprazole:** A partial dopamine agonist known for its "weight-neutral" profile and low sedative effect. It is not associated with bone marrow suppression. **High-Yield Clinical Pearls for NEET-PG:** * **Clozapine Monitoring:** ANC must be checked weekly for the first 6 months, every 2 weeks for the next 6 months, and monthly thereafter. * **Other Side Effects:** Clozapine is also notorious for causing **seizures** (dose-dependent), **sialorrhea** (excessive drooling), myocarditis, and severe constipation. * **Benefit:** It is the only antipsychotic proven to reduce the risk of **suicide** in patients with schizophrenia. * **Metabolic Syndrome:** Clozapine and Olanzapine carry the highest risk of weight gain and diabetes among antipsychotics.
Question 207: Which class of drugs is chiefly used for treating schizophrenia?
- A. Antimaniac
- B. Antidepressant
- C. Antihistaminics
- D. Antipsychotic (Correct Answer)
Explanation: **Explanation:** **Correct Answer: D. Antipsychotic** Schizophrenia is primarily characterized by an overactivity of dopamine in the mesolimbic pathway (leading to positive symptoms like hallucinations and delusions). **Antipsychotics** (also known as neuroleptics) are the mainstay of treatment. They work chiefly by blocking **D2 receptors**, thereby normalizing dopaminergic neurotransmission. They are classified into First-Generation (Typical) and Second-Generation (Atypical) antipsychotics, with the latter also targeting serotonin (5-HT2A) receptors to improve negative symptoms. **Why other options are incorrect:** * **A. Antimaniac:** These drugs (e.g., Lithium, Valproate) are used to stabilize mood in **Bipolar Affective Disorder (BPAD)**, specifically during manic episodes. * **B. Antidepressant:** These (e.g., SSRIs, SNRIs) are used to treat **Depressive disorders**, Anxiety disorders, and OCD by increasing synaptic levels of Serotonin or Norepinephrine. * **C. Antihistaminics:** While some (like Promethazine or Hydroxyzine) are used for sedation or as adjuncts in acute agitation, they are not the primary treatment for the core symptoms of schizophrenia. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC):** For treatment-resistant schizophrenia, the DOC is **Clozapine**. * **Side Effects:** Typical antipsychotics are more likely to cause **Extrapyramidal Side Effects (EPS)**, while Atypical antipsychotics are associated with **Metabolic Syndrome** (weight gain, dyslipidemia). * **Dopamine Pathways:** * *Mesolimbic:* Increased dopamine causes positive symptoms. * *Mesocortical:* Decreased dopamine causes negative symptoms. * *Nigrostriatal:* Blockade here causes EPS. * *Tuberoinfundibular:* Blockade here causes Hyperprolactinemia.
Question 208: A 31-year-old male with a mood disorder, on 30 mg of haloperidol and 100 mg of lithium, presents to the emergency room with acute onset of fever, excessive sweating, confusion, limb rigidity, and decreased communication for one day. Examination reveals tachycardia and labile blood pressure. Investigations show increased CPK enzyme levels and leucocytosis. What is the most likely diagnosis?
- A. Lithium toxicity
- B. Tardive dyskinesia
- C. Neuroleptic malignant syndrome (Correct Answer)
- D. Hypertensive encephalopathy
Explanation: ### Explanation The clinical presentation of high fever, "lead-pipe" muscle rigidity, autonomic instability (tachycardia, labile BP, sweating), and altered mental status in a patient taking high-potency antipsychotics (Haloperidol) is a classic description of **Neuroleptic Malignant Syndrome (NMS)**. **1. Why NMS is the Correct Answer:** NMS is a life-threatening idiosyncratic reaction to dopamine antagonists. The pathophysiology involves massive dopamine blockade in the nigrostriatal pathway (leading to rigidity) and hypothalamus (causing dysthermia). Laboratory findings of **elevated Creatine Phosphokinase (CPK)** due to muscle necrosis (rhabdomyolysis) and **leucocytosis** are hallmark diagnostic markers that distinguish it from other psychiatric emergencies. **2. Why Other Options are Incorrect:** * **Lithium Toxicity:** While it causes confusion and tremors, it typically presents with gastrointestinal symptoms (vomiting, diarrhea), ataxia, and coarse tremors, rather than severe "lead-pipe" rigidity and high-grade fever. * **Tardive Dyskinesia:** This is a late-onset extrapyramidal side effect characterized by involuntary choreoathetoid movements (e.g., lip-smacking, tongue protrusion). It does not present with systemic symptoms like fever or autonomic instability. * **Hypertensive Encephalopathy:** While it presents with confusion and high BP, it does not account for the generalized muscle rigidity, elevated CPK, or the specific context of recent antipsychotic use. **3. NEET-PG High-Yield Pearls:** * **Mnemonic for NMS (FEVER):** **F**ever, **E**ncephalopathy, **V**itals unstable, **E**levated enzymes (CPK), **R**igidity. * **Treatment:** Immediate discontinuation of the offending agent, aggressive cooling, and hydration. Pharmacotherapy includes **Dantrolene** (muscle relaxant) or **Bromocriptine** (dopamine agonist). * **Risk Factor:** High-potency typical antipsychotics (Haloperidol) and rapid dose escalation.
Question 209: A 45-year-old male presented to the emergency department with severe agitation and aggressive behavior. He was treated with haloperidol and became responsive and cooperative. After 8 days of treatment, he developed high-grade fever, diarrhea, confusion, and muscle rigidity. Which of the following should be used for the treatment of this condition?
- A. Diazepam
- B. Benzhexol
- C. Dantrolene (Correct Answer)
- D. High dose of haloperidol
Explanation: **Explanation:** The patient is presenting with **Neuroleptic Malignant Syndrome (NMS)**, a life-threatening idiosyncratic reaction to antipsychotics (like Haloperidol). The clinical tetrad of NMS includes **hyperpyrexia (high-grade fever), muscle rigidity ("lead-pipe" variety), autonomic instability (tachycardia, diarrhea, hypertension), and altered mental status.** **Why Dantrolene is the correct answer:** Dantrolene is a direct-acting skeletal muscle relaxant that inhibits the release of calcium from the sarcoplasmic reticulum. By reducing muscle rigidity and heat production, it addresses the core hypermetabolic state of NMS. Other specific treatments include dopamine agonists like **Bromocriptine** or Amantadine to reverse the dopamine blockade. **Analysis of Incorrect Options:** * **A. Diazepam:** While benzodiazepines are used for mild agitation or to control seizures in NMS, they are not the definitive treatment for the underlying muscle rigidity and hyperthermia. * **B. Benzhexol (Trihexyphenidyl):** This is an anticholinergic used for Acute Dystonia or Parkinsonism. In NMS, anticholinergics can worsen hyperthermia by inhibiting sweating and are generally avoided. * **D. High dose of haloperidol:** This would be fatal. NMS is caused by potent dopamine (D2) blockade; adding more haloperidol would exacerbate the condition. **NEET-PG High-Yield Pearls:** * **Key Lab Finding:** Significantly elevated **Creatine Phosphokinase (CPK)** levels and leukocytosis. * **NMS vs. Serotonin Syndrome:** NMS features "lead-pipe" rigidity and bradyreflexia, whereas Serotonin Syndrome features hyperreflexia and myoclonus. * **First step in management:** Immediate discontinuation of the offending antipsychotic agent and aggressive supportive care (cooling and hydration).
Question 210: Risperidone is most commonly used to treat which of the following disorders?
- A. Dementia
- B. Depression
- C. Schizophrenia (Correct Answer)
- D. Obsessive-compulsive disorder
Explanation: **Explanation:** **Risperidone** is a second-generation (atypical) antipsychotic. Its primary mechanism of action involves the potent blockade of **D2 (Dopamine)** receptors and **5-HT2A (Serotonin)** receptors. 1. **Why Schizophrenia is correct:** Risperidone is FDA-approved as a first-line treatment for Schizophrenia. By blocking D2 receptors in the mesolimbic pathway, it treats "positive symptoms" (hallucinations/delusions), while its 5-HT2A antagonism in the mesocortical pathway helps improve "negative symptoms" (apathy/withdrawal) and reduces the risk of Extrapyramidal Side Effects (EPS) compared to typical antipsychotics. 2. **Why other options are incorrect:** * **Dementia:** While sometimes used off-label for behavioral disturbances in dementia, it is not the primary treatment. It carries a "Black Box Warning" due to an increased risk of stroke and mortality in elderly patients with dementia-related psychosis. * **Depression:** The first-line treatments are SSRIs/SNRIs. Atypical antipsychotics (like Aripiprazole or Quetiapine) are only used as *adjuncts* in treatment-resistant cases. * **Obsessive-Compulsive Disorder (OCD):** The mainstay of treatment is high-dose SSRIs and Cognitive Behavioral Therapy (CBT). **High-Yield Clinical Pearls for NEET-PG:** * **Hyperprolactinemia:** Among atypical antipsychotics, Risperidone has the **highest risk** of increasing prolactin levels (leading to gynecomastia, galactorrhea, and amenorrhea) because it behaves like a typical antipsychotic at higher doses (>6mg). * **Metabolic Profile:** It carries a moderate risk for weight gain and metabolic syndrome (less than Olanzapine, but more than Ziprasidone). * **Active Metabolite:** **Paliperidone** is the active metabolite of Risperidone.
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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