Psychopharmacology Practice Questions

Q: Risperidone is most commonly used to treat which of the following disorders?

Schizophrenia. **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.

Q: A patient was on treatment with trifluoperazine for some time. He presents with a complaint of hyperthermia, lethargy, and sweating. Which investigations are needed?

Hemogram, CPK and renal function test. ### Explanation The clinical presentation of **hyperthermia, lethargy, and sweating** in a patient taking **Trifluoperazine** (a high-potency typical antipsychotic) strongly suggests **Neuroleptic Malignant Syndrome (NMS)**. NMS is a life-threatening idiosyncratic reaction to dopamine antagonists. **Why Option D is Correct:** To confirm the diagnosis and assess the severity of NMS, specific laboratory investigations are critical: * **Hemogram:** Typically shows **leukocytosis** (elevated WBC count), which is a diagnostic marker for NMS. * **Creatine Phosphokinase (CPK):** Severe muscle rigidity (lead-pipe rigidity) leads to muscle necrosis, causing a significant **elevation in serum CPK levels**. * **Renal Function Test (RFT):** Massive muscle breakdown leads to **myoglobinuria**, which can cause **Acute Renal Failure**. Monitoring BUN and Creatinine is vital for management. **Why Other Options are Incorrect:** * **Option A:** CT Scan is used to rule out structural brain lesions or strokes, which do not typically present with this triad of symptoms. * **Option B:** While electrolytes are important in any systemic illness, they are not specific diagnostic markers for NMS compared to CPK. * **Option C:** ECG and Chest X-ray are supportive but do not aid in the primary diagnosis of NMS or the assessment of its most common complication (rhabdomyolysis). **Clinical Pearls for NEET-PG:** * **Mnemonic for NMS (FEVER):** **F**ever, **E**ncephalopathy (lethargy), **V**itals unstable, **E**levated enzymes (CPK), **R**igidity. * **Drug of Choice:** **Dantrolene** (muscle relaxant) or **Bromocriptine** (dopamine agonist). * **Key Difference:** Unlike Serotonin Syndrome, NMS is characterized by **"Lead-pipe" rigidity** and **bradyreflexia**, whereas Serotonin Syndrome presents with hyperreflexia and myoclonus.

Q: What is the drug of choice for an elderly patient with depression and coronary artery disease?

Fluoxetine. **Explanation:** The drug of choice for depression in elderly patients, especially those with comorbid medical conditions like coronary artery disease (CAD), is a **Selective Serotonin Reuptake Inhibitor (SSRI)**. **Fluoxetine (Option A)** is an SSRI. SSRIs are preferred in cardiac patients because they lack the significant anticholinergic, antihistaminic, and alpha-1 adrenergic blocking properties that cause cardiovascular side effects. Most importantly, SSRIs do not cause orthostatic hypotension or cardiac conduction delays (unlike TCAs), making them safe for patients with CAD. **Why the other options are incorrect:** * **Dothiepin (Option B):** This is a Tricyclic Antidepressant (TCA). TCAs are strictly contraindicated in patients with heart disease because they are "quinidine-like"; they prolong the PR and QT intervals and can trigger arrhythmias or cause orthostatic hypotension, leading to falls in the elderly. * **Mianserin (Option C):** A tetracyclic antidepressant. While it has fewer cardiac effects than TCAs, it is associated with a risk of agranulocytosis in the elderly and is generally not the first-line choice compared to SSRIs. * **Amoxapine (Option D):** A tetracyclic antidepressant with dopamine-blocking properties. It carries a risk of extrapyramidal side effects and is not preferred in cardiac or elderly populations. **Clinical Pearls for NEET-PG:** * **Sertraline** is often considered the *safest* SSRI post-myocardial infarction (SADHEART trial). * **Avoid Fluoxetine** if the patient is on multiple other medications due to its long half-life and potent CYP450 inhibition; however, among the given options, it remains the best choice. * **Citalopram/Escitalopram** should be used cautiously in high doses in cardiac patients due to dose-dependent QT prolongation.

Q: Which of the following statements regarding clozapine is incorrect?

It has a narrow therapeutic window.. ### Explanation **1. Why Option C is the Correct Answer (The Incorrect Statement):** Clozapine does **not** have a narrow therapeutic window. A "narrow therapeutic window" implies that the dose required for efficacy is very close to the dose that causes toxicity (e.g., Lithium, Digoxin, Phenytoin). While Clozapine requires strict monitoring due to its side effect profile (agranulocytosis), its therapeutic range is relatively broad. Serum levels are typically maintained between **350–600 ng/mL**, but toxicity usually manifests at much higher levels (often >1000 ng/mL). **2. Analysis of Incorrect Options (Correct Statements):** * **Option A:** Clozapine was indeed withdrawn in 1975 during Phase 4 (post-marketing surveillance) after several deaths in Finland due to **agranulocytosis**. It was later reintroduced in 1989 with mandatory hematological monitoring. * **Option B:** It is the **gold standard** and the only FDA-approved drug for **treatment-resistant schizophrenia** (defined as failure of at least two different antipsychotic trials of adequate dose and duration). * **Option D:** Clozapine causes **dose-dependent seizures**. The risk increases significantly at doses above **300–450 mg/day**, reaching approximately 5% at doses above 600 mg/day. **3. High-Yield Clinical Pearls for NEET-PG:** * **Agranulocytosis:** Occurs in ~1% of patients. Monitor Absolute Neutrophil Count (ANC) weekly for the first 6 months. * **Metabolic Side Effects:** Highest risk among antipsychotics for weight gain, dyslipidemia, and Type 2 Diabetes. * **Sialorrhea:** Paradoxical excessive salivation (often nocturnal) is a common side effect. * **Myocarditis:** A rare but fatal side effect; usually occurs within the first month of treatment. * **No Extrapyramidal Symptoms (EPS):** It has the lowest risk of EPS and Tardive Dyskinesia because it is a weak D2 blocker and a potent 5HT2A antagonist.

Q: A 25-year-old man with a psychotic illness was treated with haloperidol 30mg/day. On the third day, he developed pacing and an inability to sit still. Which medication is likely to be helpful?

Propranolol. ### Explanation **Diagnosis: Akathisia** The patient is experiencing **Akathisia**, a common Extrapyramidal Side Effect (EPS) occurring within days of starting high-potency antipsychotics like Haloperidol. It is clinically characterized by subjective feelings of inner restlessness and objective signs of pacing or an inability to sit still. **Why Propranolol is Correct:** **Propranolol**, a lipophilic beta-blocker, is the **first-line treatment** for akathisia. It crosses the blood-brain barrier and acts on central beta-receptors to alleviate the symptoms of restlessness. Benzodiazepines (like Lorazepam) are considered second-line. **Why Other Options are Incorrect:** * **A. Phenytoin:** This is an antiepileptic medication used for generalized tonic-clonic seizures; it has no role in managing movement disorders caused by antipsychotics. * **C. Methylphenidate:** This is a CNS stimulant used for ADHD. It can actually worsen psychosis and agitation. * **D. Trihexyphenidyl:** This is an anticholinergic used to treat **Acute Dystonia** (muscle spasms) and **Drug-Induced Parkinsonism** (tremors/rigidity). While frequently tested, it is generally **less effective** than propranolol for akathisia. **High-Yield Clinical Pearls for NEET-PG:** * **Timeline of EPS:** 1. **Acute Dystonia:** Hours to days (Treatment: Promethazine/Trihexyphenidyl). 2. **Akathisia:** Days to weeks (Treatment: Propranolol). 3. **Drug-Induced Parkinsonism:** Weeks to months (Treatment: Trihexyphenidyl). 4. **Tardive Dyskinesia:** Months to years (Treatment: Switch to Clozapine/VMAT2 inhibitors). * **Key Differentiator:** Akathisia is often mistaken for worsening psychotic agitation. Increasing the antipsychotic dose will worsen akathisia, whereas it might improve agitation. Always look for the "pacing" keyword.

Q: Which of the following drugs could be prescribed for a child who suffers from night terrors?

Clonazepam. ### Explanation **Night terrors (Sleep Terrors)** are a type of **NREM parasomnia** that typically occurs during **Stage N3 (Slow Wave Sleep)**. The child often screams, appears terrified, and exhibits autonomic arousal (tachycardia, sweating), but remains unresponsive to comforting and has no memory of the event the next morning. **Why Clonazepam is Correct:** The pharmacological management of choice for severe or persistent night terrors involves **Benzodiazepines**, specifically **Clonazepam** or Diazepam. These drugs work by **suppressing Stage N3 sleep**, which is the specific stage where night terrors occur. By reducing the time spent in deep slow-wave sleep, the frequency of these episodes is significantly decreased. **Analysis of Incorrect Options:** * **A. Meprobamate:** An older sedative-hypnotic and anxiolytic with a high potential for addiction and toxicity. It is not used in pediatric sleep disorders. * **C. Lithium:** A mood stabilizer used primarily for Bipolar Disorder. It has no role in treating parasomnias and carries a high risk of toxicity in children. * **D. Amphetamine:** A stimulant used for ADHD and Narcolepsy. It actually disrupts sleep architecture and would likely worsen night terrors by causing sleep fragmentation. **High-Yield Clinical Pearls for NEET-PG:** * **Timing:** Night terrors occur in the **first one-third** of the night (NREM), whereas Nightmares occur in the **last one-third** (REM). * **Memory:** There is **complete amnesia** for night terrors, unlike nightmares where the child can recall the dream. * **Management:** Reassurance and "Scheduled Awakenings" are the first-line non-pharmacological treatments. Pharmacotherapy is reserved for cases where there is a risk of injury or extreme family distress. * **EEG:** Shows sudden arousal from Delta sleep.

Q: Which of the following is the best treatment for extrapyramidal symptoms?

Trihexyphenidyl. ### Explanation **Correct Answer: D. Trihexyphenidyl** **Mechanism and Rationale:** Extrapyramidal symptoms (EPS)—such as acute dystonia, parkinsonism, and akathisia—are primarily caused by a blockade of dopamine ($D_2$) receptors in the nigrostriatal pathway. This leads to a relative **excess of cholinergic activity**. Anticholinergic drugs restore the dopaminergic-cholinergic balance. **Trihexyphenidyl (Benzhexol)** is a potent centrally acting anticholinergic and is considered the first-line treatment for drug-induced parkinsonism and acute dystonia. **Analysis of Options:** * **A. Procyclidine:** While also an anticholinergic used for EPS, Trihexyphenidyl is more frequently cited in standard textbooks and clinical practice as the "best" or most common initial choice for long-term management of EPS in the Indian context. * **B. Metoclopramide:** This is a dopamine antagonist used as an antiemetic. It is a **cause** of EPS, not a treatment. * **C. Haloperidol:** This is a high-potency typical antipsychotic. It is one of the most common culprits for **inducing** EPS due to its strong $D_2$ receptor antagonism. **NEET-PG High-Yield Pearls:** * **Acute Dystonia:** The earliest EPS to appear (within hours/days). Treatment of choice: Intravenous/Intramuscular Promethazine or Benztropine. * **Akathisia:** The most common EPS. Treatment of choice: **Propranolol** (Beta-blocker). * **Tardive Dyskinesia:** Occurs after long-term use. Characterized by orofacial dyskinesia. Anticholinergics like Trihexyphenidyl can **worsen** this condition. Treatment: Switching to Clozapine or using VMAT2 inhibitors (Valbenazine). * **Drug of choice for Neuroleptic Malignant Syndrome (NMS):** Dantrolene or Bromocriptine.

Q: A patient with schizophrenia is responding well to haloperidol but has developed symptoms of parkinsonism. What is the drug of choice to treat this condition?

Anticholinergic. **Explanation:** The patient is experiencing **Drug-Induced Parkinsonism (DIP)**, a common Extrapyramidal Side Effect (EPS) of typical antipsychotics like Haloperidol. **1. Why Anticholinergics are the Drug of Choice:** Antipsychotics work by blocking Dopamine ($D_2$) receptors in the nigrostriatal pathway. In the basal ganglia, there is a functional balance between **Dopamine (inhibitory)** and **Acetylcholine (excitatory)**. When dopamine is blocked, acetylcholine becomes relatively overactive, leading to motor symptoms (tremor, rigidity, bradykinesia). **Anticholinergics** (e.g., **Benztropine, Trihexyphenidyl/Benzhexol, Biperiden**) restore this balance by reducing cholinergic activity. **2. Why other options are incorrect:** * **Levodopa (A) & Bromocriptine (B):** These are dopamine agonists used in idiopathic Parkinson’s disease. In schizophrenia, they are **contraindicated** because increasing dopamine levels can exacerbate or "rekindle" psychotic symptoms (the Dopamine Hypothesis of Schizophrenia). * **Tolcapone (C):** This is a COMT inhibitor used as an adjunct in Parkinson’s disease to prevent levodopa breakdown. It has no role in treating EPS and carries a risk of hepatotoxicity. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice for Akathisia:** Beta-blockers (Propranolol). * **Drug of Choice for Acute Dystonia:** Intravenous/Intramuscular Anticholinergics (Promethazine or Benztropine). * **Tardive Dyskinesia:** Unlike other EPS, this is caused by dopamine receptor supersensitivity; anticholinergics can actually **worsen** it. Treatment involves Valbenazine or Deutetrabenazine (VMAT2 inhibitors). * **Amantadine:** An alternative for DIP if anticholinergics are poorly tolerated.

Q: A 25-year-old man with major depression discusses the potential benefits and side effects of various antidepressants with his psychiatrist. He clearly indicates that he does not want a medication that could decrease his libido or interfere with his ability to obtain and maintain an erection. Which of the listed antidepressants would be appropriate for this patient?

Bupropion. **Explanation:** The correct answer is **Bupropion**. Sexual dysfunction (decreased libido, erectile dysfunction, and anorgasmia) is one of the most common reasons for non-compliance with antidepressant therapy. **Why Bupropion is correct:** Bupropion is an **Atypical Antidepressant** that acts as a **Norepinephrine-Dopamine Reuptake Inhibitor (NDRI)**. Unlike most other antidepressants, it does not have significant serotonergic activity. Sexual side effects are primarily mediated by the stimulation of 5-HT2 receptors; since Bupropion lacks this mechanism, it has a "neutral" effect on sexual function and is often used as an alternative or an adjunct to reverse SSRI-induced sexual dysfunction. **Why the other options are incorrect:** * **Sertraline (Option D):** As an **SSRI**, it is the class most frequently associated with sexual dysfunction (up to 60-70% of patients). It increases synaptic serotonin, which inhibits sexual desire and arousal. * **Clomipramine & Amitriptyline (Options B & C):** These are **Tricyclic Antidepressants (TCAs)**. They cause sexual dysfunction through multiple mechanisms, including serotonergic activity and strong anticholinergic effects (which can interfere with the parasympathetic-mediated erectile response). Clomipramine, specifically, is a potent serotonin reuptake inhibitor and has the highest rate of sexual side effects among TCAs. **NEET-PG High-Yield Pearls:** * **Weight Neutrality:** Bupropion is also preferred in patients concerned about weight gain. * **Contraindication:** It must be avoided in patients with **Seizure disorders** or **Eating disorders** (Bulimia/Anorexia) as it lowers the seizure threshold. * **Smoking Cessation:** It is also FDA-approved for smoking cessation. * **Other "Sexually Safe" Antidepressants:** Mirtazapine and Vilazodone.

Question 1

Risperidone is most commonly used to treat which of the following disorders?

Accepted Answer

Schizophrenia

Answer

Dementia

Answer

Depression

Answer

Obsessive-compulsive disorder

Question 2

A patient was on treatment with trifluoperazine for some time. He presents with a complaint of hyperthermia, lethargy, and sweating. Which investigations are needed?

Accepted Answer

Hemogram, CPK and renal function test

Answer

CT Scan brain & hemogram

Answer

Hemogram, Electrolyte level and creatinine

Answer

ECG, Chest X-ray and hemogram

Question 3

What is the drug of choice for an elderly patient with depression and coronary artery disease?

Accepted Answer

Fluoxetine

Answer

Dothiepin

Answer

Mianserin

Answer

Amoxapine

Question 4

Which of the following statements regarding clozapine is incorrect?

Accepted Answer

It has a narrow therapeutic window.

Answer

It was withdrawn from the market during phase 4 clinical trials.

Answer

It is used in treatment-resistant schizophrenia.

Answer

It can cause seizures at doses exceeding 300mg/day.

Question 5

A 25-year-old man with a psychotic illness was treated with haloperidol 30mg/day. On the third day, he developed pacing and an inability to sit still. Which medication is likely to be helpful?

Accepted Answer

Propranolol

Answer

Phenytoin

Answer

Methylphenidate

Answer

Trihexyphenidyl

Question 6

Which of the following drugs could be prescribed for a child who suffers from night terrors?

Accepted Answer

Clonazepam

Answer

Meprobamate

Answer

Lithium

Answer

Amphetamine

Question 7

Which of the following is the best treatment for extrapyramidal symptoms?

Accepted Answer

Trihexyphenidyl

Answer

Procyclidine

Answer

Metoclopramide

Answer

Haloperidol

Question 8

A patient with schizophrenia is responding well to haloperidol but has developed symptoms of parkinsonism. What is the drug of choice to treat this condition?

Accepted Answer

Anticholinergic

Answer

Levodopa

Answer

Bromocriptine

Answer

Tolcapone

Question 9

Which of the following statements is FALSE regarding Neuroleptic Malignant Syndrome (NMS)?

Accepted Answer

An increase in Creatinine Phosphokinase (CPK) always indicates NMS.

Answer

Combining antipsychotics and antidepressants increases the risk of NMS.

Answer

First use of an injectable antipsychotic is a risk factor.

Answer

Catatonic symptoms and autonomic dysfunction are features of NMS.

Question 10

A 25-year-old man with major depression discusses the potential benefits and side effects of various antidepressants with his psychiatrist. He clearly indicates that he does not want a medication that could decrease his libido or interfere with his ability to obtain and maintain an erection. Which of the listed antidepressants would be appropriate for this patient?

Accepted Answer

Bupropion

Answer

Clomipramine

Answer

Amitriptyline

Answer

Sertraline

Psychopharmacology — MCQs

Psychopharmacology — MCQs

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