Psychopharmacology Practice Questions

Q: Which drug is most useful in treating an episode of antipsychotic-induced acute dystonia?

Promethazine. **Explanation:** **Mechanism and Correct Answer:** Acute dystonia is an Extrapyramidal Side Effect (EPS) caused by a blockade of dopamine (D2) receptors in the nigrostriatal pathway, leading to a relative **excess of cholinergic activity**. To restore the neurochemical balance, drugs with potent **central anticholinergic properties** are required. **Promethazine (Option B)** is a first-generation antihistamine with significant anticholinergic activity, making it highly effective for reversing acute dystonic reactions (such as torticollis, grimacing, or oculogyric crisis). Other parenteral options frequently used include Benztropine or Trihexyphenidyl. **Analysis of Incorrect Options:** * **A. Haloperidol:** This is a high-potency typical antipsychotic and a potent D2 blocker. It is a common *cause* of acute dystonia; administering it would worsen the condition. * **C. Phenobarbitone:** This is a barbiturate used for seizures or sedation. It has no anticholinergic activity and does not address the underlying dopamine-acetylcholine imbalance. * **D. Lorazepam:** While benzodiazepines can provide sedation and mild muscle relaxation, they are not the primary treatment of choice for dystonia. They are generally reserved for Akathisia or as adjunctive therapy if anticholinergics are insufficient. **NEET-PG High-Yield Pearls:** * **Acute Dystonia:** The earliest EPS to appear (within hours to days). * **Drug of Choice (DOC):** Central anticholinergics (Promethazine, Benztropine). * **Akathisia:** Most common EPS; DOC is **Propranolol**. * **Drug-Induced Parkinsonism:** DOC is **Trihexyphenidyl** (Centrally acting anticholinergic). * **Tardive Dyskinesia:** Occurs after long-term use; characterized by "fly-catcher tongue." Treatment involves switching to Clozapine or using VMAT-2 inhibitors (Valbenazine).

Q: Which of the following is NOT true about clozapine?

Has no anti-suicide property.. **Explanation:** **Clozapine** is a unique "atypical" antipsychotic reserved for treatment-resistant schizophrenia. 1. **Why Option B is the correct answer (The False Statement):** Clozapine is one of the few psychotropic drugs with proven **anti-suicide properties**. It is FDA-approved specifically for reducing the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder. Therefore, stating it has "no anti-suicide property" is clinically incorrect. (Note: Lithium is the other major drug with anti-suicide effects in mood disorders). 2. **Analysis of Incorrect Options (True Statements):** * **Option A:** Clozapine carries a risk of **agranulocytosis**. Strict hematological monitoring is required. If the Total Leukocyte Count (WBC) falls below **3000–3500/mm³** or the Absolute Neutrophil Count (ANC) falls below **1500/mm³**, the drug must be discontinued to prevent fatal infections. * **Option C:** **Carbamazepine** is a potent bone marrow suppressant. Combining it with Clozapine synergistically increases the risk of agranulocytosis. Additionally, Carbamazepine is a CYP3A4 inducer which lowers Clozapine levels. * **Option D:** Unlike typical antipsychotics that bind strongly to D2 receptors, Clozapine has a high affinity for **D4 receptors** and 5-HT2A receptors, with relatively weak D2 blockade. This explains its low incidence of Extrapyramidal Side Effects (EPS). **High-Yield Clinical Pearls for NEET-PG:** * **Drug of choice:** Treatment-resistant schizophrenia (failed 2 trials of other antipsychotics). * **Side Effects:** Sialorrhea (hypersalivation), seizures (dose-dependent), myocarditis, and significant weight gain. * **Benefit:** It is the only antipsychotic that does not cause Tardive Dyskinesia and rarely causes Prolactin elevation.

Q: What is the drug of choice for antipsychotic-induced Parkinsonism?

Trihexyphenidyl. **Explanation:** **Mechanism and Correct Answer:** Antipsychotic-induced Parkinsonism is a type of **Extrapyramidal Side Effect (EPS)** caused by the blockade of dopamine (D2) receptors in the nigrostriatal pathway. This blockade creates a relative **excess of cholinergic activity** (acetylcholine). To restore the balance between dopamine and acetylcholine, **centrally acting anticholinergics** are used. **Trihexyphenidyl (Benzhexol)** is the drug of choice because it effectively crosses the blood-brain barrier to antagonize muscarinic receptors, thereby alleviating tremors, rigidity, and bradykinesia. Other drugs in this class include Benztropine and Biperiden. **Analysis of Incorrect Options:** * **Pimavanserin:** This is a selective 5-HT2A inverse agonist. It is specifically used for **Parkinson’s disease psychosis** (hallucinations in patients who already have PD), not for treating drug-induced EPS. * **Droxidopa:** A synthetic precursor of norepinephrine used primarily for treating **neurogenic orthostatic hypotension**. * **Pramipexole:** A dopamine agonist used in idiopathic Parkinson’s disease and Restless Leg Syndrome. It is generally avoided in antipsychotic-induced Parkinsonism because it can worsen the underlying psychosis by stimulating dopamine receptors. **High-Yield NEET-PG Pearls:** * **Drug of Choice for Acute Dystonia:** Parenteral Promethazine or Benztropine. * **Drug of Choice for Akathisia:** Propranolol (Beta-blocker). * **Drug of Choice for Tardive Dyskinesia:** Valbenazine or Deutetrabenazine (VMAT-2 inhibitors). * **Note:** Levodopa is **contraindicated** in drug-induced Parkinsonism as it can precipitate or worsen psychosis.

Q: Which of the following drugs is NOT used in the management of attention deficit hyperactivity disorder in children?

Imipramine. **Explanation:** The management of Attention Deficit Hyperactivity Disorder (ADHD) primarily involves increasing catecholamine levels (dopamine and norepinephrine) in the prefrontal cortex to improve focus and impulse control. **Why Imipramine is the Correct Answer:** While **Imipramine** (a Tricyclic Antidepressant) was historically used as a third-line agent for ADHD due to its effect on norepinephrine reuptake, it is **no longer recommended** for use in children for this indication. The primary reason is its significant **cardiotoxicity** (risk of arrhythmias and sudden cardiac death) and a narrow therapeutic index. In modern clinical practice and for NEET-PG purposes, it is considered obsolete for ADHD management. **Analysis of Other Options:** * **Methylphenidate (Option D):** This is the **drug of choice** for ADHD. It acts by blocking the reuptake of dopamine and norepinephrine. * **Amphetamines (Option B):** These are first-line stimulants that increase the release of catecholamines from storage vesicles into the synaptic cleft. * **Modafinil (Option A):** Though primarily used for narcolepsy, Modafinil is used **off-label** in children with ADHD who do not respond to or cannot tolerate first-line stimulants. **High-Yield Clinical Pearls for NEET-PG:** * **First-line Non-Stimulant:** **Atomoxetine** (a selective NE reuptake inhibitor) is the preferred non-stimulant, especially if there is a risk of substance abuse. * **Alpha-2 Agonists:** Clonidine and Guanfacine are also used as adjuncts or alternatives. * **Side Effects:** Stimulants (Methylphenidate/Amphetamines) can cause **growth suppression** and insomnia; monitoring height and weight is essential.

Q: Which of the following are atypical (second generation or newer) antipsychotics?

Risperidone. **Explanation:** Antipsychotics are classified into **Typical (First Generation)** and **Atypical (Second Generation)** based on their mechanism of action and side-effect profile. **Why Risperidone is correct:** Risperidone is a prototypical **Atypical Antipsychotic**. Unlike typical agents that primarily block Dopamine (D2) receptors, atypical antipsychotics are **Serotonin-Dopamine Antagonists (SDAs)**. They block both 5-HT2A and D2 receptors. This dual action reduces Extrapyramidal Side Effects (EPS) and is more effective in treating the negative symptoms of schizophrenia (e.g., apathy, social withdrawal). **Analysis of other options:** * **Aripiprazole:** This is a **Third Generation** antipsychotic. It acts as a **D2 partial agonist** (Dopamine System Stabilizer). While often grouped with atypicals in broad categories, it is pharmacologically distinct. * **Olanzapine:** This is also an **Atypical Antipsychotic**. (Note: In many MCQ formats, if multiple options are correct, the "most" representative or the one specified in the key is chosen; however, clinically, both Risperidone and Olanzapine are Second Generation). * **Pimozide:** This is a **Typical (First Generation)** antipsychotic belonging to the Diphenylbutylpiperidine class. It is highly potent and specifically used in Tourette’s syndrome and Delusional Parasitosis (Ekbom syndrome). **High-Yield NEET-PG Pearls:** * **Clozapine:** The first atypical antipsychotic; gold standard for **treatment-resistant schizophrenia**. Watch for **agranulocytosis** (requires mandatory WBC monitoring). * **Metabolic Syndrome:** Olanzapine and Clozapine carry the highest risk of weight gain and diabetes. * **Hyperprolactinemia:** Among atypicals, **Risperidone** has the highest risk of increasing prolactin levels. * **Ziprasidone:** Associated with **QT interval prolongation**; avoid in patients with cardiac history.

Q: A 26-year-old man with schizophrenia and tardive dyskinesia. Which is the most appropriate pharmacotherapeutic agent?

Clozapine. **Explanation:** The correct answer is **Clozapine**. **Why Clozapine is the drug of choice:** Tardive Dyskinesia (TD) is a late-onset extrapyramidal side effect (EPS) caused by the long-term blockade of dopamine (D2) receptors, leading to receptor supersensitivity. When a patient with schizophrenia develops TD, the primary strategy is to switch them to an atypical antipsychotic with the lowest risk of EPS. **Clozapine** is the gold standard in this scenario because it has a very low affinity for D2 receptors and a high affinity for D4 and serotonin (5-HT2A) receptors. It is the only antipsychotic that does not cause TD and may even suppress existing dyskinetic movements. **Why other options are incorrect:** * **Haloperidol:** This is a high-potency typical antipsychotic with strong D2 antagonism. It is a leading cause of TD and would worsen the condition. * **Valproic acid:** This is a mood stabilizer/anti-epileptic. While it may be used as an adjunct in schizoaffective disorders, it has no role in treating the core symptoms of schizophrenia or reversing TD. * **Paroxetine:** This is an SSRI used for depression and anxiety. It does not treat psychosis and can occasionally worsen movement disorders through indirect serotonergic effects on dopamine. **High-Yield Clinical Pearls for NEET-PG:** * **VMAT2 Inhibitors:** Drugs like **Valbenazine** and **Deutetrabenazine** are now FDA-approved specifically for the treatment of TD. * **Clozapine Monitoring:** Remember the "No Blood, No Drug" rule. Clozapine requires mandatory monitoring of Absolute Neutrophil Count (ANC) due to the risk of **agranulocytosis** (most common in the first 18 weeks). * **Other Side Effects:** Clozapine is associated with seizures (dose-dependent), myocarditis, and significant weight gain/metabolic syndrome.

Q: Lithium is best used in which of the following conditions?

Manic-depressive disorder (bipolar). **Explanation:** **Lithium** is the gold-standard treatment and the "drug of choice" for the prophylaxis and maintenance of **Bipolar Affective Disorder (BPAD)**, historically referred to as **Manic-depressive disorder**. It is highly effective in treating acute manic episodes and preventing future relapses of both mania and depression. * **Why Option A is correct:** Lithium’s primary mechanism involves modulating second messenger systems (inhibiting inositol monophosphatase) and stabilizing neurotransmission. It is uniquely effective in classic BPAD, particularly in patients with a "mania-followed-by-depression" sequence and a positive family history of lithium response. * **Why Options B & D are incorrect:** While Lithium can be used as an **augmentation strategy** in treatment-resistant Unipolar or Major Depressive Disorder, it is not the first-line treatment. Selective Serotonin Reuptake Inhibitors (SSRIs) are the preferred initial therapy for these conditions. * **Why Option C is incorrect:** Rapid cycling (defined as ≥4 mood episodes in 12 months) is a known predictor of **poor response** to Lithium. In such cases, **Valproate** or Carbamazepine are considered superior and are the preferred mood stabilizers. **High-Yield Clinical Pearls for NEET-PG:** * **Therapeutic Index:** Lithium has a narrow therapeutic index. Target serum levels are **0.8–1.2 mEq/L** for acute mania and **0.6–1.0 mEq/L** for maintenance. * **Anti-suicidal Property:** Lithium is one of the few psychotropic drugs (along with Clozapine) proven to reduce the risk of suicide in bipolar patients. * **Teratogenicity:** Use in pregnancy is associated with **Ebstein’s Anomaly** (atrialization of the right ventricle). * **Side Effects:** Common issues include fine tremors, polyuria (nephrogenic diabetes insipidus), and hypothyroidism.

Q: What is the treatment for tardive dyskinesia?

Clonazepam and vitamin E. **Explanation:** **Tardive Dyskinesia (TD)** is a delayed-onset extrapyramidal side effect caused by long-term use of dopamine receptor blockers (antipsychotics). It is characterized by involuntary, choreoathetoid movements, most commonly involving the orofacial region (e.g., tongue protrusion, lip-smacking). **Why Option B is Correct:** The management of TD is challenging. The first step is usually to reduce the dose of the offending agent or switch to a second-generation antipsychotic like Clozapine. For symptomatic treatment: * **Vitamin E:** Acts as an antioxidant to combat free radical damage to striatal neurons caused by chronic dopamine blockade. * **Clonazepam:** A benzodiazepine that enhances GABAergic tone, which helps suppress involuntary movements. * *Note:* Modern gold-standard treatments now include VMAT2 inhibitors (Valbenazine, Deutetrabenazine), but in the context of standard NEET-PG options, Vitamin E and Clonazepam remain classic choices. **Why Other Options are Incorrect:** * **A. Dantrolene sodium:** This is a muscle relaxant used specifically for **Neuroleptic Malignant Syndrome (NMS)** and Malignant Hyperthermia. * **C. Pacitane (Trihexyphenidyl):** This is an anticholinergic used for *Acute Dystonia* and *Drug-induced Parkinsonism*. Crucially, anticholinergics often **worsen** TD symptoms. * **D. Propranolol:** This beta-blocker is the drug of choice for **Akathisia** (subjective restlessness). **High-Yield Clinical Pearls for NEET-PG:** 1. **Pathophysiology:** TD is thought to be due to **dopamine receptor supersensitivity** in the nigrostriatal pathway. 2. **Risk Factors:** Old age, female gender, and long-term use of typical antipsychotics (e.g., Haloperidol). 3. **AIMS Scale:** The Abnormal Involuntary Movement Scale is used for screening and monitoring TD. 4. **Clozapine:** The antipsychotic with the lowest risk of causing TD and often used to manage patients who develop it.

Q: Which second-generation antipsychotic functions as a first-generation antipsychotic in large doses?

Risperidone. **Explanation:** **Risperidone** is a second-generation (atypical) antipsychotic that exhibits a unique dose-dependent pharmacological profile [1]. At standard therapeutic doses (2–6 mg/day), it acts as a serotonin-dopamine antagonist (SDA), blocking 5-HT2A receptors more than D2 receptors. This balance reduces extrapyramidal side effects (EPS). However, at **high doses (>6–8 mg/day)**, its D2 receptor occupancy increases significantly, exceeding the 80% threshold. At this level, it behaves like a **first-generation (typical) antipsychotic**, leading to a high incidence of EPS and hyperprolactinemia. **Analysis of Incorrect Options:** * **A. Clozapine:** The "gold standard" for treatment-resistant schizophrenia. It has very low D2 affinity and high 5-HT2A/D4 affinity [1]; it almost never causes EPS, regardless of the dose. * **B. Quetiapine:** Known for "rapid dissociation" from D2 receptors. Even at high doses, it maintains a low risk of EPS, making it preferred in Parkinson’s disease patients with psychosis [2]. * **D. Lurasidone:** An atypical antipsychotic with potent 5-HT7 antagonism. While it can cause akathisia, it does not typically transition into a "first-generation" profile in the same dose-dependent manner as Risperidone. **NEET-PG High-Yield Pearls:** * **Hyperprolactinemia:** Among atypicals, Risperidone is the most notorious for causing elevated prolactin (due to strong D2 blockade in the tuberoinfundibular pathway). * **Active Metabolite:** Risperidone is metabolized to **Paliperidone** (9-hydroxyrisperidone) [1]. * **Aripiprazole:** Known as a "Dopamine System Stabilizer" (Partial D2 agonist) [1]. * **Olanzapine:** Associated with the highest risk of metabolic syndrome (weight gain, dyslipidemia) [1].

Q: Which of the following is an absolute contraindication for the use of lithium?

Renal failure. **Explanation:** **Lithium** is the gold standard mood stabilizer for Bipolar Affective Disorder (BPAD). Understanding its pharmacokinetics is crucial for NEET-PG: Lithium is a monovalent cation that is **exclusively excreted by the kidneys** and is not metabolized by the liver. 1. **Why Renal Failure is the Correct Answer:** Since Lithium is handled by the kidneys similarly to sodium (reabsorbed in the proximal tubule), any impairment in renal function leads to a drastic decrease in clearance. This results in rapid accumulation and **Lithium Toxicity**, which can be fatal or lead to permanent neurological damage (SILDCOR syndrome). Therefore, significant renal failure is an **absolute contraindication**. 2. **Analysis of Incorrect Options:** * **Glaucoma:** Unlike tricyclic antidepressants (TCAs) or antipsychotics with anticholinergic properties, Lithium does not significantly affect intraocular pressure. It is safe to use in glaucoma. * **Epilepsy:** Lithium is not contraindicated in epilepsy. While it can lower the seizure threshold at toxic levels, it is generally safe at therapeutic levels. In fact, some studies suggest it may have mild anticonvulsant properties. * **Angina:** While Lithium can cause EKG changes (like T-wave flattening/inversion), it is not an absolute contraindication for stable angina. However, it should be used with caution in patients with sick sinus syndrome. **High-Yield Clinical Pearls for NEET-PG:** * **Teratogenicity:** Causes **Ebstein’s Anomaly** (tricuspid valve displacement) if taken in the 1st trimester. * **Therapeutic Index:** Very narrow (0.6–1.2 mEq/L). Toxicity starts >1.5 mEq/L. * **Drug Interactions:** **NSAIDs, Thiazides, and ACE inhibitors** increase Lithium levels by decreasing renal clearance (High-yield mnemonic: **"NAT"**). * **Side Effects:** Nephrogenic Diabetes Insipidus, Hypothyroidism, and Fine Tremors.

Question 1

Which drug is most useful in treating an episode of antipsychotic-induced acute dystonia?

Accepted Answer

Promethazine

Answer

Haloperidol

Answer

Phenobarbitone

Answer

Lorazepam

Question 2

Which of the following is NOT true about clozapine?

Accepted Answer

Has no anti-suicide property.

Answer

Should be discontinued if WBC count is < 3500/dl.

Answer

Should not be used along with carbamazepine.

Answer

The action is more on D4 receptors than D2 receptors.

Question 3

What is the drug of choice for antipsychotic-induced Parkinsonism?

Accepted Answer

Trihexyphenidyl

Answer

Pimavanserin

Answer

Droxidopa

Answer

Pramipexole

Question 4

Which of the following drugs is NOT used in the management of attention deficit hyperactivity disorder in children?

Accepted Answer

Imipramine

Answer

Modafinil

Answer

Amphetamines

Answer

Methylphenidate

Question 5

Which of the following are atypical (second generation or newer) antipsychotics?

Accepted Answer

Risperidone

Answer

Aripiprazole

Answer

Pimozide

Answer

Olanzapine

Question 6

A 26-year-old man with schizophrenia and tardive dyskinesia. Which is the most appropriate pharmacotherapeutic agent?

Accepted Answer

Clozapine

Answer

Valproic acid

Answer

Haloperidol

Answer

Paroxetine

Question 7

Lithium is best used in which of the following conditions?

Accepted Answer

Manic-depressive disorder (bipolar)

Answer

Unipolar depression

Answer

Manic-depressive disorder with rapid cycling

Answer

Major depressive disorder

Question 8

What is the treatment for tardive dyskinesia?

Accepted Answer

Clonazepam and vitamin E

Answer

Dantrolene sodium

Answer

Pacitine

Answer

Propranolol

Question 9

Which second-generation antipsychotic functions as a first-generation antipsychotic in large doses?

Accepted Answer

Risperidone

Answer

Clozapine

Answer

Quetiapine

Answer

Lurasidone

Question 10

Which of the following is an absolute contraindication for the use of lithium?

Accepted Answer

Renal failure

Answer

Glaucoma

Answer

Epilepsy

Answer

Angina

Psychopharmacology — MCQs

Psychopharmacology — MCQs

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