Drugs in Psychiatric Disorders Practice Questions

Q: Which of the following is NOT true regarding olanzapine?

It has less epileptogenic action than phenothiazines.. **Explanation:** Olanzapine is a potent **Second-Generation Antipsychotic (SGA)** or atypical antipsychotic. Understanding its side-effect profile is crucial for NEET-PG. **Why Option D is the Correct Answer (The "False" Statement):** Olanzapine, along with Clozapine, is known to **lower the seizure threshold** significantly. In fact, olanzapine has a **higher epileptogenic potential** compared to many typical antipsychotics like phenothiazines (e.g., Chlorpromazine) and other SGAs like Risperidone. Therefore, stating it has "less" epileptogenic action is incorrect. **Analysis of Other Options:** * **Option A (Anti-muscarinic action):** Olanzapine has a high affinity for M1 receptors, leading to marked anticholinergic side effects such as dry mouth, constipation, and urinary retention. * **Option B (Weight gain):** Olanzapine is notorious for causing significant **metabolic syndrome**, characterized by profound weight gain, dyslipidemia, and type 2 diabetes mellitus. It is second only to Clozapine in this regard. * **Option C (Prolactin levels):** Unlike Risperidone or typical antipsychotics, Olanzapine causes only a **mild and transient** increase in prolactin levels, rarely leading to clinical galactorrhea or gynecomastia. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** It acts as a 5-HT2A and D2 receptor antagonist (SDA). * **Metabolic Monitoring:** Patients on Olanzapine must have regular monitoring of BMI, blood glucose, and lipid profiles. * **Smoking Interaction:** Smoking induces the **CYP1A2** enzyme, which can decrease olanzapine plasma levels. * **Drug of Choice:** It is highly effective for negative symptoms of schizophrenia and as a mood stabilizer in Bipolar Disorder.

Q: Central anticholinergics are used in the treatment of all the following conditions except:

Neuroleptic malignant syndrome. **Explanation:** The correct answer is **Neuroleptic malignant syndrome (NMS)** because its pathophysiology is primarily linked to severe dopamine blockade rather than a simple cholinergic-dopaminergic imbalance. **1. Why NMS is the exception:** NMS is a life-threatening idiosyncratic reaction to antipsychotics characterized by the "tetrad" of fever, rigidity, altered mental status, and autonomic instability. The treatment of choice involves immediate cessation of the offending agent and the use of **Dantrolene** (a direct-acting muscle relaxant) or **Bromocriptine** (a dopamine agonist). Central anticholinergics are ineffective here and may actually worsen hyperthermia by inhibiting sweating. **2. Analysis of other options (Extrapyramidal Side Effects - EPSEs):** * **Acute Dystonia:** Characterized by sudden muscle spasms (e.g., torticollis). It is caused by an acute drop in dopamine, leading to relative cholinergic overactivity. **IV/IM Benztropine or Promethazine** are first-line treatments. * **Parkinsonism (Drug-induced):** Presents with tremors and rigidity. Central anticholinergics (e.g., **Trihexyphenidyl/Benzhexol**) help restore the balance between dopamine and acetylcholine in the nigrostriatal pathway. * **Akathisia:** Defined as subjective motor restlessness. While **Beta-blockers (Propranolol)** are the drug of choice, central anticholinergics are considered a second-line treatment option. **Clinical Pearls for NEET-PG:** * **Tardive Dyskinesia:** Remember that anticholinergics **worsen** tardive dyskinesia; the treatment involves switching to Clozapine or using VMAT-2 inhibitors (Valbenazine). * **Drug of Choice Summary:** * Acute Dystonia $\rightarrow$ Benztropine * Akathisia $\rightarrow$ Propranolol * NMS $\rightarrow$ Dantrolene/Bromocriptine

Q: Tricyclic antidepressants are contraindicated in:

Glaucoma. **Explanation:** Tricyclic Antidepressants (TCAs), such as Amitriptyline and Imipramine, possess potent **anticholinergic (antimuscarinic) properties**. These drugs block M1 receptors, leading to pupillary dilation (mydriasis) and cycloplegia. In patients with narrow-angle glaucoma, mydriasis can further obstruct the drainage of aqueous humor through the canal of Schlemm, acutely increasing intraocular pressure and potentially precipitating an attack of **acute angle-closure glaucoma**. Therefore, they are strictly contraindicated in such patients. **Analysis of Incorrect Options:** * **B. Brain Tumor:** While TCAs lower the seizure threshold (caution in epilepsy), they are not specifically contraindicated in brain tumors unless the tumor is causing uncontrolled seizures or specific neurological complications where anticholinergic effects interfere with monitoring. * **C. Bronchial Asthma:** TCAs do not cause bronchoconstriction. In fact, their anticholinergic effect might theoretically cause slight bronchodilation, though they are not used for this purpose. * **D. Hypertension:** TCAs are more commonly associated with **orthostatic hypotension** (due to alpha-1 blockade). While they can occasionally cause tachycardia or interact with antihypertensives, hypertension is not a primary contraindication. **High-Yield NEET-PG Pearls:** * **Cardiac Toxicity:** TCAs are cardiotoxic in overdose, causing **prolongation of the QRS complex** and QTc interval. Sodium bicarbonate is the antidote for TCA-induced arrhythmias. * **Side Effect Profile:** Remember the "3 Cs" of TCA toxicity: **C**oma, **C**onvulsions, and **C**ardiotoxicity. * **Other Contraindications:** Recent Myocardial Infarction (MI), heart block, and prostatic hypertrophy (due to urinary retention).

Q: What is the most common anomaly seen in the fetus of a mother taking lithium carbonate?

Cardiac deformities. **Explanation:** Lithium carbonate, a mood stabilizer used for Bipolar Affective Disorder, is a known human teratogen. When taken during the first trimester of pregnancy, it primarily affects the developing heart. **1. Why Cardiac Deformities are correct:** Lithium exposure is classically associated with **Ebstein’s Anomaly**. This is a congenital heart defect characterized by the downward displacement of the tricuspid valve leaflets into the right ventricle, leading to "atrialization" of the ventricle and severe tricuspid regurgitation. While the absolute risk is low (approx. 1-2 per 1,000 exposures), it represents a 10-20 fold increase compared to the general population, making cardiac malformations the most characteristic and common anomaly associated with the drug. **2. Why other options are incorrect:** * **Neural Tube Defects (NTDs):** These are most commonly associated with **Valproate** and **Carbamazepine** due to their interference with folate metabolism. * **Limb Reduction:** This is the hallmark of **Thalidomide** (Phocomelia). Lithium does not typically affect limb bud development. * **Genitourinary Deformities:** These are more commonly associated with **ACE inhibitors** (renal dysgenesis) or fetal hydantoin syndrome (Phenytoin). **High-Yield Clinical Pearls for NEET-PG:** * **Ebstein’s Anomaly:** Look for "Box-shaped heart" on X-ray and "WPW Syndrome" on ECG in these neonates. * **Management:** If a pregnant woman is on Lithium, a **Fetal Echocardiogram** is recommended at 18–22 weeks of gestation to screen for cardiac defects. * **Breastfeeding:** Lithium is generally discouraged during breastfeeding as it is excreted in milk and can cause "Floppy Infant Syndrome" (cyanosis and hypotonia).

Q: Which of the following are extrapyramidal side effects of antipsychotics?

Dystonia, Akathisia, and Parkinsonism. **Explanation:** Extrapyramidal Side Effects (EPS) are movement disorders caused by the blockade of **D2 receptors in the nigrostriatal pathway**. This pathway regulates motor control, and its inhibition by antipsychotics (especially typical ones like Haloperidol) leads to an imbalance between dopamine and acetylcholine. **1. Why Option C is Correct:** The classic triad of early-onset EPS includes: * **Acute Dystonia:** Spasms of muscles (e.g., torticollis, oculogyric crisis). Occurs within hours to days. * **Akathisia:** Subjective feeling of motor restlessness (inability to sit still). This is the most common EPS. * **Parkinsonism:** Tremors, rigidity, and bradykinesia. Occurs within weeks. * *(Note: Tardive Dyskinesia is a late-onset EPS involving choreoathetoid movements.)* **2. Why Other Options are Incorrect:** * **Seizures:** While antipsychotics (especially Clozapine) can lower the seizure threshold, seizures are considered a neurological adverse effect, not an extrapyramidal motor symptom. * **Diarrhea:** Antipsychotics typically have **anticholinergic** properties, which cause constipation, not diarrhea. **NEET-PG High-Yield Pearls:** * **Treatment of Acute Dystonia/Parkinsonism:** Central anticholinergics like **Benztropine** or **Promethazine**. * **Treatment of Akathisia:** Drug of choice is **Propranolol** (Beta-blocker). * **Hyperprolactinemia:** Also caused by D2 blockade, but in the **tuberoinfundibular pathway**, leading to galactorrhea and gynecomastia. * **Lowest EPS Risk:** Quetiapine and Clozapine (Atypical antipsychotics).

Q: Which of the following drugs has a high affinity for 5-HT2 receptors in the brain, does not cause extrapyramidal dysfunction or hematotoxicity, and is reported to increase the risk of significant QT prolongation?

Ziprasidone. **Explanation:** The question describes the profile of an **Atypical Antipsychotic (Second Generation Antipsychotic)**. These drugs are characterized by a higher affinity for **5-HT2A receptors** compared to D2 receptors, which reduces the risk of Extrapyramidal Side Effects (EPS) [1]. **Why Ziprasidone is the correct answer:** * **Mechanism:** It has a high 5-HT2A/D2 affinity ratio [1]. * **Safety Profile:** Unlike typical antipsychotics, it causes minimal to no EPS. Crucially, it is **not associated with hematotoxicity** (unlike Clozapine) [1]. * **Cardiac Warning:** Ziprasidone is notorious for causing **significant QT interval prolongation**, which can lead to life-threatening arrhythmias like Torsades de Pointes [3]. This makes it contraindicated in patients with a history of arrhythmias or recent MI. **Analysis of Incorrect Options:** * **Chlorpromazine:** A typical (first-generation) antipsychotic. It has a high risk of EPS and significant sedative/anticholinergic effects, but its primary mechanism is D2 blockade, not 5-HT2 dominance. * **Clozapine:** While it has high 5-HT2 affinity and no EPS, it is famously associated with **agranulocytosis (hematotoxicity)**, which the question explicitly excludes [1]. * **Olanzapine:** An atypical antipsychotic with low EPS risk, but its primary metabolic side effect is **significant weight gain** and hyperglycemia, not significant QT prolongation compared to Ziprasidone [2]. **NEET-PG High-Yield Pearls:** * **QT Prolongation:** Remember the mnemonic "Ziprasidone and Thioridazine" as the top antipsychotics causing QT issues [3]. * **Weight Neutrality:** Ziprasidone and Aripiprazole are preferred in patients concerned about weight gain [2]. * **Clozapine Monitoring:** Requires mandatory WBC count monitoring due to the risk of agranulocytosis [1].

Q: Which of the following is a dopamine and noradrenaline reuptake inhibitor?

Bupropion. **Bupropion** is the correct answer because it belongs to the class of **NDRIs (Norepinephrine and Dopamine Reuptake Inhibitors)**. Unlike most antidepressants that primarily target serotonin, Bupropion inhibits the transporters for both dopamine and noradrenaline, increasing their synaptic concentrations [2]. This unique mechanism makes it particularly effective for patients with "atypical" depression characterized by low energy, fatigue, and poor concentration. Analysis of Incorrect Options: * **Clozapine (A):** An atypical antipsychotic. It primarily acts as an antagonist at $D_2$ and $5-HT_{2A}$ receptors. It is the gold standard for treatment-resistant schizophrenia but is not a reuptake inhibitor. * **Zolpidem (B):** A non-benzodiazepine sedative-hypnotic ("Z-drug"). It acts as a selective agonist at the $\alpha_1$ subunit of the $GABA_A$ receptor complex. It is used for the short-term treatment of insomnia. * **Mianserin (D):** An atypical antidepressant classified as a NaSSA (Noradrenergic and Specific Serotonergic Antidepressant). It works primarily by blocking presynaptic $\alpha_2$ adrenoceptors rather than inhibiting reuptake. High-Yield Clinical Pearls for NEET-PG: * **Smoking Cessation:** Bupropion is FDA-approved for smoking cessation as it reduces nicotine cravings and withdrawal symptoms [1]. * **Sexual Dysfunction:** Unlike SSRIs, Bupropion does **not** cause sexual dysfunction or significant weight gain, making it a preferred choice for patients concerned about these side effects [1]. * **Seizure Risk:** The most significant adverse effect is a dose-dependent increase in seizure risk. It is strictly **contraindicated** in patients with epilepsy or eating disorders (bulimia/anorexia) due to electrolyte imbalances that further lower the seizure threshold [1].

Q: Administration of disulfiram in an alcoholic can cause all these side effects except?

Hypertension. The correct answer is **Hypertension**. **Mechanism of Action:** Disulfiram acts by inhibiting the enzyme **Aldehyde Dehydrogenase (ALDH)**. When a patient taking disulfiram consumes alcohol, the metabolism of ethanol is arrested at the stage of **Acetaldehyde**. This leads to a 5-to-10-fold accumulation of acetaldehyde in the blood, resulting in the **Disulfiram-Ethanol Reaction (DER)** [1]. **Why Hypertension is the Correct Answer:** The hallmark of the Disulfiram-Ethanol Reaction is **Hypotension**, not hypertension. The accumulation of acetaldehyde causes intense peripheral vasodilation and releases histamine, leading to a significant drop in blood pressure. In severe cases, this can progress to shock or cardiovascular collapse. **Analysis of Incorrect Options:** * **Flushing (A):** This is the most common and earliest sign of the reaction, caused by acetaldehyde-induced vasodilation of the facial and neck vessels. * **Headache (B):** Often described as a "throbbing" headache, this occurs due to the dilation of intracranial blood vessels. * **Nausea (C):** Acetaldehyde is a potent emetic stimulus; nausea and projectile vomiting are classic components of the DER. **High-Yield Clinical Pearls for NEET-PG:** * **Disulfiram-like reaction:** Several other drugs can cause a similar reaction when taken with alcohol. Mnemonic: **"PM C G"** (**P**rocarbazine, **M**etronidazole, **C**ephalosporins like Cefoperazone/Cefotetan, **G**riseofulvin, and Sulfonylureas). * **Dopamine Beta-Hydroxylase Inhibition:** Disulfiram also inhibits this enzyme, leading to decreased norepinephrine synthesis, which further contributes to hypotension and potential psychosis. * **Contraindication:** It should never be administered to a patient in a state of alcohol intoxication or without their full knowledge.

Q: Which of the following antidepressants causes hypertensive crisis?

Phenelzine. **Explanation** The correct answer is **Phenelzine**. Phenelzine is a non-selective, irreversible **Monoamine Oxidase Inhibitor (MAOI)**. **Why Phenelzine causes Hypertensive Crisis:** MAOIs inhibit the enzyme monoamine oxidase, which is responsible for breaking down tyramine in the gastrointestinal tract and liver. When a patient taking an MAOI consumes **tyramine-rich foods** (e.g., aged cheese, red wine, cured meats), tyramine enters the systemic circulation and acts as an indirect sympathomimetic. It displaces large amounts of stored norepinephrine from presynaptic vesicles into the synaptic cleft, leading to severe vasoconstriction and a potentially fatal **hypertensive crisis** (the "Cheese Reaction"). **Analysis of Incorrect Options:** * **A. Dapoxetine:** A short-acting Selective Serotonin Reuptake Inhibitor (SSRI) used primarily for premature ejaculation. It does not significantly affect norepinephrine levels. * **B. Duloxetine:** A Serotonin-Norepinephrine Reuptake Inhibitor (SNRI). While it can cause a modest increase in blood pressure, it does not trigger a sudden hypertensive crisis via the tyramine pathway. * **C. Clomipramine:** A Tricyclic Antidepressant (TCA) that primarily inhibits serotonin reuptake. Its main side effects are anticholinergic and cardiac arrhythmias, not hypertensive crisis. **NEET-PG High-Yield Pearls:** * **Antidote:** The treatment of choice for an MAOI-induced hypertensive crisis is **Phentolamine** (an alpha-blocker). * **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**. * **Other MAOIs:** Isocarboxazid and Tranylcypromine are also non-selective MAOIs associated with this risk.

Question 1

Which of the following is NOT true regarding olanzapine?

Accepted Answer

It has less epileptogenic action than phenothiazines.

Answer

It causes marked anti-muscarinic action.

Answer

It causes weight gain.

Answer

It causes a mild increase in prolactin.

Question 2

Central anticholinergics are used in the treatment of all the following conditions except:

Accepted Answer

Neuroleptic malignant syndrome

Answer

Akathisia

Answer

Parkinsonism

Answer

Acute dystonia

Question 3

Tricyclic antidepressants are contraindicated in:

Accepted Answer

Glaucoma

Answer

Brain tumor

Answer

Bronchial asthma

Answer

Hypertension

Question 4

What is the most common anomaly seen in the fetus of a mother taking lithium carbonate?

Accepted Answer

Cardiac deformities

Answer

Neural tube defect

Answer

Limb reduction

Answer

Genitourinary deformities

Question 5

What is the most likely medication to cause disinterest in food with protein/calorie malnutrition?

Accepted Answer

Selective serotonin reuptake inhibitors (SSRIs)

Answer

Mineral oil

Answer

Diuretics

Answer

Isoniazid (INH)

Question 6

Which of the following are extrapyramidal side effects of antipsychotics?

Accepted Answer

Dystonia, Akathisia, and Parkinsonism

Answer

Dystonia, Akathisia, and Seizures

Answer

Akathisia, Seizures, and Diarrhea

Answer

Dystonia, Seizures, and Parkinsonism

Question 7

Which of the following drugs has a high affinity for 5-HT2 receptors in the brain, does not cause extrapyramidal dysfunction or hematotoxicity, and is reported to increase the risk of significant QT prolongation?

Accepted Answer

Ziprasidone

Answer

Chlorpromazine

Answer

Clozapine

Answer

Olanzapine

Question 8

Which of the following is a dopamine and noradrenaline reuptake inhibitor?

Accepted Answer

Bupropion

Answer

Clozapine

Answer

Zolpidem

Answer

Mianserin

Question 9

Administration of disulfiram in an alcoholic can cause all these side effects except?

Accepted Answer

Hypertension

Answer

Flushing

Answer

Headache

Answer

Nausea

Question 10

Which of the following antidepressants causes hypertensive crisis?

Accepted Answer

Phenelzine

Answer

Dapoxetine

Answer

Duloxetine

Answer

Clomipramine

Drugs in Psychiatric Disorders — MCQs

Drugs in Psychiatric Disorders — MCQs

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