Drugs in Psychiatric Disorders — MCQs

Drugs in Psychiatric Disorders Indian Medical PG Practice Questions and MCQs

Question 261: What class of medication is used to treat schizophrenia?

A. Antidepressants
B. Antipsychotics (Correct Answer)
C. Antiepileptics
D. Mood stabilizers

Explanation: **Explanation:** **Antipsychotics** (also known as neuroleptics) are the primary pharmacological treatment for schizophrenia. The underlying medical concept is the **Dopamine Hypothesis**, which suggests that schizophrenia is caused by overactivity of dopamine in the brain. Antipsychotics work primarily by blocking **Dopamine D2 receptors** in the mesolimbic pathway to alleviate positive symptoms like hallucinations and delusions. They are divided 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:** * **Antidepressants:** Primarily used for Major Depressive Disorder and Anxiety disorders. They increase synaptic levels of serotonin and norepinephrine, which does not address the core pathophysiology of schizophrenia. * **Antiepileptics:** Used to control seizures by stabilizing neuronal membranes. While some (like Valproate) are used in psychiatry, they are not primary treatments for schizophrenia. * **Mood Stabilizers:** These (e.g., Lithium) are the gold standard for Bipolar Affective Disorder (BPAD) to manage mania and prevent relapse, rather than treating primary psychosis. **High-Yield NEET-PG Pearls:** * **Drug of Choice (DOC) for Resistant Schizophrenia:** Clozapine (requires monitoring for agranulocytosis). * **Common Side Effect:** Typical antipsychotics (e.g., Haloperidol) frequently cause **Extrapyramidal Symptoms (EPS)** due to nigrostriatal D2 blockade. * **Hyperprolactinemia:** A common side effect of Risperidone due to D2 blockade in the tuberoinfundibular pathway. * **Metabolic Syndrome:** A major concern with Atypical antipsychotics, especially Olanzapine and Clozapine.

Question 262: Regarding the use of Lithium in maniac-depressive psychosis, what is the true statement?

A. Lithium is indicated for monotherapy of acute episodes.
B. Monitoring of serum concentration is not useful for guiding dose adjustment.
C. Lithium can result in leucocytosis. (Correct Answer)
D. Lithium can result in hypothyroidism on long-term use.

Explanation: ### Explanation **Correct Option: C. Lithium can result in leucocytosis.** Lithium has a well-documented effect on the hematological system where it stimulates granulopoiesis. It increases the production of white blood cells (specifically neutrophils) by enhancing the release of granulocyte colony-stimulating factor (G-CSF). This results in a **benign, reversible leucocytosis**. In clinical practice, this "side effect" is sometimes exploited to treat clozapine-induced agranulocytosis or chemotherapy-induced neutropenia. **Analysis of Incorrect Options:** * **A. Lithium is indicated for monotherapy of acute episodes:** While Lithium is a first-line agent for maintenance, it has a **slow onset of action** (5–10 days). Therefore, in acute manic episodes, it is rarely used as monotherapy and is typically combined with fast-acting atypical antipsychotics or benzodiazepines to achieve immediate control. * **B. Monitoring of serum concentration is not useful:** This is false. Lithium has a **narrow therapeutic index** (0.5–1.2 mEq/L). Therapeutic Drug Monitoring (TDM) is mandatory to prevent toxicity and ensure efficacy. * **D. Lithium can result in hypothyroidism on long-term use:** While this statement is medically **true**, it is not the "best" answer in the context of many standardized exams where Option C is the classic "textbook" physiological effect highlighted. However, in many clinical scenarios, both C and D are correct. In the context of this specific question format, leucocytosis is the primary intended learning point regarding Lithium's unique systemic effects. **High-Yield Clinical Pearls for NEET-PG:** * **Therapeutic Levels:** Acute Mania (0.8–1.2 mEq/L); Prophylaxis (0.5–0.8 mEq/L); Toxicity (>1.5 mEq/L). * **Renal Effects:** Causes Nephrogenic Diabetes Insipidus (treated with Amiloride). * **Teratogenicity:** Ebstein’s Anomaly (tricuspid valve displacement). * **Drug Interactions:** Thiazides, NSAIDs, and ACE inhibitors increase Lithium levels (decreased clearance). * **Thyroid:** Inhibits iodine coupling and thyroid hormone release (Goiter/Hypothyroidism).

Question 263: Which of the following is an atypical antipsychotic with the least metabolic side effects?

A. Risperidone
B. Ziprasidone (Correct Answer)
C. Haloperidol
D. Quetiapine

Explanation: ***Ziprasidone*** - Among the atypical (second-generation) antipsychotics, **Ziprasidone** has the lowest risk regarding adverse **metabolic side effects**, including **weight gain**, dyslipidemia, and insulin resistance. - Due to its minimal impact on metabolic parameters, it is a preferred choice for patients with pre-existing **cardiovascular risk factors** or obesity. *Haloperidol* - Haloperidol is a **first-generation (typical)** antipsychotic, which primarily risks **extrapyramidal symptoms (EPS)** and elevated prolactin, rather than being an atypical agent. - While its metabolic risk is generally lower than high-risk atypicals (e.g., Olanzapine), it is not the correct classification for answering a question focusing on *atypical* drugs. *Risperidone* - Risperidone is an atypical antipsychotic but carries a **moderate to high risk** of causing significant **weight gain** and **hyperprolactinemia**. - Its metabolic profile is considerably worse than that of Ziprasidone or Aripiprazole. *Quetiapine* - Quetiapine carries a substantial risk profile regarding metabolic adverse effects, specifically high rates of **sedation** and clinically significant **weight gain**. - It is frequently linked to the development of **dyslipidemia** and **Type 2 diabetes mellitus**.

Question 264: A patient was given an antipsychotic drug, haloperidol, and the patient developed acute dystonia. Which is the next best step?

A. Give Fluphenazine
B. Give Benztropine (Correct Answer)
C. Increase dose of haloperidol
D. Change to clozapine

Explanation: ***Give Benztropine***- **Acute dystonia** is a severe extrapyramidal symptom (EPS) requiring rapid intervention, often treated intramuscularly or intravenously.- **Benztropine** (an anticholinergic agent) is the drug of choice for the immediate management of acute dystonia, working to restore the balance between dopamine and acetylcholine.*Change to clozapine*- While **clozapine** has a significantly lower risk of causing acute dystonia, it is not the initial treatment for an acute episode due to its slow titration requirements and side-effect profile.- Switching to clozapine is a long-term strategy for patients intolerant to other antipsychotics, not an acute rescue medication.*Give Fluphenazine*- **Fluphenazine** is a high-potency first-generation antipsychotic, similar to haloperidol, which also carries a high risk of EPS.- Administering another high-potency antipsychotic would perpetuate the excessive **dopaminergic blockade** responsible for the acute dystonia.*Increase dose of haloperidol*- **Acute dystonia** is a direct dose-related side effect of D2 receptor blockade by haloperidol in the nigrostriatal pathway.- Increasing the dose of **haloperidol** would worsen the underlying neurochemical imbalance, thereby intensifying the dystonic symptoms.

Question 265: A 12-year-old child presents with palpitations, tremors, dry mouth, heart rate 130 bpm, respiratory rate 34/min. Which of the following substances is most likely responsible?

A. TCA (tricyclic antidepressant) (Correct Answer)
B. Opioid
C. Propranolol
D. Lithium

Explanation: ***TCA (tricyclic antidepressant)***- The constellation of tachycardia (palpitations, HR 130 bpm), tremors, and dry mouth suggests a severe mixed toxidrome, highly characteristic of a TCA overdose.- TCAs exhibit potent **anticholinergic effects** (dry mouth, tachycardia) combined with severe **sodium channel blockade** (contributing to CNS symptoms like tremors and cardiovascular instability) resulting in this critical presentation [1].*Lithium*- Lithium toxicity primarily presents with progressive **neurological symptoms** like ataxia, coarse tremors, lethargy, and seizures.- While tremor is present, the severe **tachycardia** and pronounced **dry mouth** are not typical primary features of the lithium toxidrome.*Opioid*- Opioid toxicity is defined by the classic triad of **miosis** (pinpoint pupils), **respiratory depression** (bradypnea), and altered consciousness.- The patient is profoundly **tachycardic** (130 bpm) and **tachypneic** (34/min), which directly contradicts the expected findings of an opioid overdose.*Propranolol*- Propranolol is a **beta-blocker**, and its overdose typically causes **bradycardia**, hypotension, and potential non-cardiogenic pulmonary edema.- The patient's presentation of significant **tachycardia** (130 bpm) rules out poisoning by a beta-blocking agent.

Question 266: A patient with schizophrenia, developed muscular dystonia and was treated for it. The patient now presents with complaints of dry mouth, dizziness, and hypotension. What is the most likely drug causing these side effects?

A. Benzotropine (Correct Answer)
B. Propranolol
C. Risperidone
D. Haloperidol

Explanation: ***Benzotropine***- This drug is an **anticholinergic agent** administered specifically to treat **extrapyramidal symptoms (EPS)** like acute muscular dystonia caused by antipsychotics.- **Dry mouth** is a characteristic manifestation of its peripheral **anticholinergic side effects**, while **dizziness and hypotension** can occur due to central effects or potentiation of adrenergic blockade, particularly when co-administered with antipsychotics.*Risperidone*- Although Risperidone (an atypical antipsychotic) commonly causes EPS and strong **orthostatic hypotension** due to **alpha-1 adrenergic blockade** (dizziness/hypotension), it has moderate anticholinergic activity, making it less likely to be the sole cause of prominent dry mouth.- The patient's presentation suggests a new medication was introduced *after* the dystonia developed; Risperidone was likely the cause of the *initial* dystonia.*Haloperidol*- Haloperidol, a high-potency typical antipsychotic, is a common cause of **muscular dystonia** (EPS).- It has relatively **low anticholinergic activity** and is therefore an improbable cause of severe **dry mouth** compared to agents like Benzotropine.*Propranolol*- Propranolol is a **beta-blocker** typically used to treat antipsychotic-induced **akathisia** or tremor, not acute dystonia.- Its most prominent side effects are related to beta-blockade, such as **bradycardia** and fatigue; it is not routinely associated with significant **dry mouth**.

Question 267: A 38-year-old professor with depression requests you to prescribe an antidepressant that would be least likely to cause sexual dysfunction. Which of the following drugs would you prescribe?

A. Bupropion (Correct Answer)
B. Venlafaxine
C. Fluoxetine
D. Escitalopram

Explanation: ***Bupropion***- Bupropion is a **norepinephrine-dopamine reuptake inhibitor (NDRI)** that differs structurally and mechanically from SSRIs and SNRIs. - It is known for its relatively neutral effect on sexual function, often having the **lowest incidence** of sexual side effects among commonly prescribed antidepressants, and is sometimes used to treat SSRI-induced sexual dysfunction.*Escitalopram*- As a **selective serotonin reuptake inhibitor (SSRI)**, escitalopram frequently causes sexual side effects such as decreased libido, delayed orgasm, and anorgasmia.- This class of drugs elevates **serotonin levels**, which is strongly implicated in causing sexual dysfunction.*Venlafaxine*- Venlafaxine is a **serotonin-norepinephrine reuptake inhibitor (SNRI)**, and its serotonergic component carries a medium-to-high risk of causing sexual dysfunction.- The common sexual side effects include **erectile dysfunction** in men and reduced arousal in women.*Fluoxetine*- Fluoxetine is a commonly prescribed **SSRI** with a significant association with sexual side effects, including inhibited orgasm and reduced libido.- Its long half-life means that these adverse effects, if they occur, can persist following **discontinuation**.

Question 268: A psychiatrist prescribes lithium for a patient who is diagnosed with bipolar disorder. Which of the following statements is incorrect regarding lithium?

A. Lithium is teratogenic if given to pregnant females
B. Lithium toxicity is exacerbated with thiazide
C. Hemodialysis is not useful in lithium overdose (Correct Answer)
D. Lithium can decrease thyroid hormone levels

Explanation: ***Correct Answer: Hemodialysis is not useful in lithium overdose*** - This statement is **INCORRECT** (making it the right answer to this negation question) - **Hemodialysis IS actually very useful** in severe lithium toxicity - Lithium has low molecular weight (~7 Da), minimal protein binding, and small volume of distribution, making it effectively removed by hemodialysis - **Indications for hemodialysis in lithium toxicity:** Lithium levels >4 mEq/L, severe clinical toxicity (seizures, altered consciousness), or renal failure *Incorrect Option: Lithium is teratogenic if given to pregnant females* - This statement is TRUE, so it's not the answer - Lithium causes **Ebstein's anomaly** (downward displacement of tricuspid valve) when given in first trimester - Risk is 1-2% (20x higher than general population) - FDA pregnancy category D *Incorrect Option: Lithium toxicity is exacerbated with thiazide* - This statement is TRUE, so it's not the answer - Thiazide diuretics decrease renal lithium clearance by promoting sodium depletion - This leads to **compensatory increase in proximal tubular reabsorption** of both sodium and lithium - NSAIDs and ACE inhibitors also increase lithium levels similarly *Incorrect Option: Lithium can decrease thyroid hormone levels* - This statement is TRUE, so it's not the answer - Lithium inhibits thyroid hormone synthesis and release, causing **hypothyroidism in 5-35%** of patients - Mechanism: Inhibits iodine uptake and blocks thyroid hormone release - Requires regular thyroid function monitoring (TSH, T3, T4) during lithium therapy

Question 269: Which of the following psychoactive substances is a new, rapidly acting antidepressant?

A. Ketamine (Correct Answer)
B. Bupropion
C. Haloperidol
D. Cannabinoids

Explanation: ***Ketamine*** - It is an **NMDA receptor antagonist** that produces a rapid and often sustained antidepressant effect, typically within hours, making it a new class of rapidly acting antidepressants. - **Esketamine** (a derivative) is specifically approved for **treatment-resistant depression** and acute suicidal ideation. *Bupropion* - This is a traditional antidepressant classified as a **Norepinephrine and Dopamine Reuptake Inhibitor (NDRI)**. - Like most conventional antidepressants (SSRIs, SNRIs), Bupropion has a **delayed onset of action**, usually requiring weeks for clinical efficacy. *Haloperidol* - This substance is a typical or first-generation **antipsychotic** used primarily to treat conditions involving psychosis, such as schizophrenia and acute mania. - Its primary function involves potent blockade of **Dopamine D2 receptors**, and it is not used in the management of primary depression. *Cannabinoids* - These agents primarily modulate the **endocannabinoid system (CB1 and CB2 receptors)**, and while they have CNS effects, they are generally not used as primary, rapid-acting antidepressants. - Research into cannabinoids for mood is complex, and they may sometimes lead to dysphoria or **anxiety/psychosis exacerbation**.

Question 270: Which drug has propensity to cause such involuntary movements?

A. Flupenthixol (Correct Answer)
B. Clozapine
C. Risperidone
D. Tetrabenazine

Explanation: ***Flupenthixol*** - The image displays various **involuntary movements** of the face, characteristic of **tardive dyskinesia**. - **Flupenthixol** is a **typical (first-generation) antipsychotic** with **high D2 receptor blockade**, giving it the **highest propensity** among the options to cause **extrapyramidal symptoms** including tardive dyskinesia. - Typical antipsychotics are the **most common cause** of drug-induced tardive dyskinesia due to chronic dopamine receptor blockade. *Risperidone* - **Risperidone** is an atypical antipsychotic with **moderate risk** of extrapyramidal symptoms and tardive dyskinesia, particularly at higher doses. - While it can cause TD, its risk is **lower than typical antipsychotics** like flupenthixol but **higher than other atypical antipsychotics** like clozapine or quetiapine. *Tetrabenazine* - **Tetrabenazine** is a **monoamine depletor** (VMAT2 inhibitor) used to **treat tardive dyskinesia and chorea** in Huntington's disease. - It can cause **drug-induced parkinsonism and akathisia**, but does **not typically cause tardive dyskinesia** itself. - It works by depleting presynaptic dopamine rather than blocking postsynaptic receptors. *Clozapine* - **Clozapine** is an atypical antipsychotic with the **lowest risk of extrapyramidal symptoms** and tardive dyskinesia among all antipsychotics. - It has **weak D2 receptor affinity** and strong 5-HT2A antagonism, making it protective against TD. - Often chosen specifically for patients at high risk of or with existing movement disorders.

Practice by Chapter

Antipsychotics: Typical and Atypical

Practice Questions

Antidepressants: SSRIs and SNRIs

Practice Questions

Tricyclic Antidepressants

Practice Questions

MAO Inhibitors

Practice Questions

Mood Stabilizers

Practice Questions

Anxiolytics

Practice Questions

Drugs for ADHD

Practice Questions

Drugs for Sleep Disorders

Practice Questions

Drugs for Dementia

Practice Questions

Drug-Induced Psychiatric Symptoms

Practice Questions

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