Drugs in Psychiatric Disorders — MCQs

Drugs in Psychiatric Disorders Indian Medical PG Practice Questions and MCQs

Question 311: Which FDA approved drug is used for refractory schizophrenia?

A. Amoxapine
B. Haloperidol
C. Clozapine (Correct Answer)
D. Penfluridol

Explanation: ***Clozapine*** - **Clozapine** is an **atypical antipsychotic** uniquely approved for the treatment of **refractory schizophrenia**, where other antipsychotics have failed. - Its efficacy in treatment-resistant cases is attributed to its complex pharmacological profile, including antagonism of multiple **dopamine** and **serotonin receptors**. *Amoxapine* - **Amoxapine** is a **tetracyclic antidepressant** with some antipsychotic properties due to **dopamine receptor blockade**, but it is not a first-line or approved treatment for refractory schizophrenia. - It's primarily used for **major depressive disorder** and carries a risk of inducing **extrapyramidal symptoms**. *Haloperidol* - **Haloperidol** is a **first-generation (typical) antipsychotic** effective in treating acute psychotic symptoms but generally not used as the agent of choice for **refractory schizophrenia**. - Its primary mechanism involves potent **D2 dopamine receptor blockade**, which often leads to significant **extrapyramidal side effects**. *Penfluridol* - **Penfluridol** is a **long-acting, first-generation antipsychotic** that is used for maintenance treatment of schizophrenia, but it is not specifically indicated or uniquely effective for **refractory cases**. - It has a prolonged duration of action, making it suitable for patients requiring less frequent dosing to improve **medication adherence**.

Question 312: What is the mechanism of action of tianeptine?

A. NMDA receptor antagonism
B. Serotonin reuptake enhancement
C. Mu-opioid receptor agonism
D. AMPA receptor potentiation (Correct Answer)

Explanation: ***AMPA receptor potentiation*** - Tianeptine has been shown to modulate **glutamatergic activity** by potentiating **AMPA receptor function**, promoting neuroplasticity [1]. - This effect is thought to contribute to its **antidepressant and anxiolytic properties**, particularly in stress-related neuronal changes [1]. *Mu-opioid receptor agonism* - While tianeptine does exhibit some weak **mu-opioid receptor agonist activity** at higher doses, it is not considered its primary therapeutic mechanism for antidepressant effects. - The opioid effects are usually associated with its **abuse potential** and are distinct from its primary antidepressant action. *Serotonin reuptake enhancement* - Tianeptine is unique among antidepressants for its property of **enhancing serotonin reuptake**, rather than inhibiting it. - Although it increases serotonin reuptake, this effect alone does not fully explain its antidepressant action, and its **glutamatergic modulation** is considered more critical. *NMDA receptor antagonism* - **NMDA receptor antagonism** is associated with drugs like ketamine, which have rapid antidepressant effects by blocking the receptor [2]. - Tianeptine does not directly act as an NMDA receptor antagonist; instead, it influences synaptic plasticity through **AMPA receptor modulation**.

Question 313: Which of the following is true about ziprasidone?

A. Has anti-depressant properties
B. Not safe in cardiac patients due to QT prolongation risk
C. Lower risk of extrapyramidal symptoms compared to typical antipsychotics (Correct Answer)
D. Commonly causes significant weight gain

Explanation: ***Lower risk of extrapyramidal symptoms compared to typical antipsychotics*** - **Ziprasidone** is an **atypical antipsychotic**, which generally carries a **lower risk of extrapyramidal symptoms (EPS)** compared to older, first-generation (typical) antipsychotics. - This is primarily due to its different receptor binding profile, including weaker **D2 dopamine receptor antagonism** and significant **5-HT2A serotonin receptor antagonism**. *Commonly causes significant weight gain* - **Incorrect**: Ziprasidone is considered one of the most **weight-neutral antipsychotics**, causing minimal weight gain. - Unlike **olanzapine** and **clozapine**, which are associated with significant weight gain and metabolic side effects, ziprasidone has a favorable metabolic profile. - This makes it a preferred option when weight gain is a concern. *Has anti-depressant properties* - While ziprasidone can be used as adjunctive therapy in **bipolar depression**, it is not classified as a primary antidepressant. - Its efficacy in mood symptoms is attributed to **serotonin** and **dopamine** modulation, but it lacks the direct mechanism of action of true antidepressants. - It is primarily indicated for **schizophrenia** and **bipolar disorder**, not major depressive disorder. *Not safe in cardiac patients due to QT prolongation risk* - **Partially true but too absolute**: Ziprasidone does carry a dose-dependent risk of **QT interval prolongation**. - However, it is not completely contraindicated in cardiac patients; rather, it requires **careful cardiac monitoring**, **baseline ECG**, and avoidance in patients with known QT prolongation. - With appropriate precautions and patient selection, it can be used safely under medical supervision.

Question 314: The clinical effects of antidepressant drugs are mainly based on?

A. Reduction in neurotransmitter levels
B. Change in neurotransmitter receptor sensitivity (Correct Answer)
C. Modification of neurotransmitter signaling pathways
D. Inhibition of neurotransmitter reuptake

Explanation: ***B. Change in neurotransmitter receptor sensitivity*** - While many antidepressants initially alter neurotransmitter levels by blocking reuptake, their delayed therapeutic effects (weeks) are thought to be mediated by **adaptive changes** in postsynaptic receptor sensitivity and gene expression, leading to **downregulation of hypersensitive receptors**. - This **receptor plasticity** is crucial for long-term clinical improvement, as the brain adapts to sustained changes in neurotransmitter availability. *A. Reduction in neurotransmitter levels* - This option is incorrect as antidepressants generally aim to **increase** the functional availability of **neurotransmitters** like serotonin and norepinephrine within the synaptic cleft. - A reduction in neurotransmitter levels would typically exacerbate depressive symptoms, not alleviate them. *C. Modification of neurotransmitter signaling pathways* - While antidepressants do ultimately affect intracellular signaling pathways, this is often a **downstream consequence** of changes in receptor sensitivity and neurotransmitter binding, rather than the primary *main* basis of their clinical effects. - This option is broader and less precise than the change in receptor sensitivity, missing the direct impact on how neurons respond to available neurotransmitters. *D. Inhibition of neurotransmitter reuptake* - This describes the **initial and acute mechanism of action** for many antidepressant classes (e.g., SSRIs, SNRIs) by increasing the concentration of neurotransmitters in the synaptic cleft. - However, the **clinical antidepressant effects** often take several weeks to manifest, suggesting that this acute increase in neurotransmitter availability is not the sole or primary basis for long-term symptom relief, but rather initiates the adaptive changes in receptor sensitivity.

Question 315: All the following drugs are used to prevent relapse and maintain abstinence in cases of alcohol use disorder except?

A. Acamprosate
B. Naltrexone
C. Propranolol (Correct Answer)
D. Disulfiram

Explanation: ***Propranolol*** - **Propranolol** is a **beta-blocker** primarily used to treat conditions like hypertension, angina, and anxiety. - While it can help manage some **symptoms associated with alcohol withdrawal**, such as tremors and tachycardia, it is **not indicated or effective for preventing relapse or maintaining abstinence** from alcohol use disorder. *Disulfiram* - **Disulfiram** works by inhibiting **acetaldehyde dehydrogenase**, leading to an unpleasant accumulation of acetaldehyde if alcohol is consumed. - This adverse reaction serves as a **deterrent** to drinking alcohol, helping to prevent relapse [1], [2]. *Acamprosate* - **Acamprosate** is believed to restore the balance between **excitatory (glutamate)** and **inhibitory (GABA)** neurotransmission in the brain, which is often disrupted in alcohol dependence. - It helps reduce cravings and the **negative reinforcement** associated with protracted withdrawal, aiding in the maintenance of abstinence [1]. *Naltrexone* - **Naltrexone** is an **opioid receptor antagonist** that works by blocking the euphoric and pleasurable effects of alcohol [1]. - By reducing the **rewarding effects of alcohol**, it helps decrease cravings and subsequently the risk of relapse [1].

Question 316: Which receptor is most commonly targeted by typical antipsychotics?

A. D1
B. D2 (Correct Answer)
C. D3
D. D4

Explanation: ***Correct: D2*** - **Typical antipsychotics** (first-generation antipsychotics) primarily exert their therapeutic effects by blocking **dopamine D2 receptors** in the mesolimbic pathway, thereby reducing positive symptoms of psychosis such as hallucinations and delusions. - The degree of **D2 receptor blockade** correlates directly with **clinical efficacy** for typical antipsychotics. - High-potency typical antipsychotics like haloperidol have strong D2 receptor affinity, while low-potency agents like chlorpromazine also work primarily through D2 blockade. - D2 blockade in the nigrostriatal pathway is responsible for extrapyramidal side effects (EPS), a hallmark of typical antipsychotics. *Incorrect: D1* - **D1 receptors** are dopaminergic receptors involved in cognitive and motor functions, but their blockade is not the primary mechanism of action of typical antipsychotics. - While some antipsychotics may have D1 affinity, this is not what defines typical antipsychotics or drives their therapeutic efficacy. *Incorrect: D3* - **Dopamine D3 receptors** are involved in the limbic system and may play a role in some antipsychotic effects, but they are not the primary target for **typical antipsychotics**. - Some newer atypical antipsychotics have higher affinity for D3 receptors, but this is not characteristic of first-generation typical agents. *Incorrect: D4* - **D4 receptors** have high affinity for certain atypical antipsychotics like **clozapine**, but this is not the main receptor target for **typical antipsychotics**. - D4 receptor selectivity is more associated with atypical rather than typical antipsychotic profiles.

Question 317: In which condition is Atomoxetine primarily indicated?

A. ADHD (Correct Answer)
B. Treatment of nocturnal enuresis
C. Management of temper tantrums
D. Treatment of patent ductus arteriosus

Explanation: ***ADHD*** - **Atomoxetine** is a **norepinephrine reuptake inhibitor** primarily used for the treatment of **Attention-Deficit/Hyperactivity Disorder (ADHD)** in children, adolescents, and adults [1]. - It helps improve symptoms such as **inattention**, **hyperactivity**, and **impulsivity** by increasing the concentration of norepinephrine in the brain [1], [2]. *Treatment of nocturnal enuresis* - While some medications for **ADHD** (like **imipramine**) can be used off-label for **nocturnal enuresis**, atomoxetine is **not a primary indication** for this condition [3]. - Management of **nocturnal enuresis** typically involves behavioral interventions, desmopressin, or tricyclic antidepressants [3]. *Management of temper tantrums* - **Temper tantrums** are primarily behavioral issues and are generally managed through **behavioral therapy** and parenting strategies. - **Atomoxetine** is not indicated as a primary treatment for temper tantrums; if tantrums are a symptom of an underlying disorder like ADHD, addressing the ADHD might indirectly help. *Treatment of patent ductus arteriosus* - **Patent ductus arteriosus (PDA)** is a cardiovascular condition typically seen in newborns, involving a persistent opening between the aorta and pulmonary artery. - Treatment for PDA usually involves **NSAIDs (like indomethacin or ibuprofen)** or surgical ligation, not atomoxetine.

Question 318: Which of the following statements about aripiprazole is true?

A. It has low sedating potential
B. It has 5HT1A partial agonist action
C. Only antipsychotic with D2 partial agonist activity
D. It is used in the treatment of acute mania (Correct Answer)

Explanation: ***It is used in the treatment of acute mania*** - Aripiprazole is a **second-generation antipsychotic** approved for the treatment of **acute manic and mixed episodes** associated with bipolar I disorder. - This is a **major FDA-approved indication** and represents one of its most clinically significant uses, making it the best answer among the true statements. - Its efficacy in stabilizing mood through its unique partial agonism at dopamine D2 and serotonin 5-HT1A receptors, along with antagonism at 5-HT2A receptors, makes it suitable for this indication. *It has 5HT1A partial agonist action* - This statement is **factually TRUE** - aripiprazole does have **5-HT1A partial agonist action** as part of its pharmacological profile. - However, this mechanistic detail alone does not represent its primary clinical significance or most distinguishing therapeutic feature. - Its unique mechanism also involves **D2 partial agonism** and 5-HT2A antagonism. *It has low sedating potential* - This statement is also **TRUE** - aripiprazole is well-established as having **low sedating potential** compared to most other antipsychotics. - This is actually one of its **distinguishing advantages** and a key feature that differentiates it from highly sedating antipsychotics like quetiapine or olanzapine. - While sedation can occur in some patients, it is relatively uncommon, and the low sedation profile is a recognized clinical benefit. *Only antipsychotic with D2 partial agonist activity* - This statement is **FALSE** - aripiprazole was one of the first antipsychotics with significant **D2 partial agonist activity**, but it is **not the *only* one**. - Other antipsychotics, such as **brexpiprazole** and **cariprazine**, also exhibit D2 partial agonist activity, distinguishing them from traditional D2 antagonists.

Question 319: What electrolyte imbalance is commonly associated with lithium use?

A. Hypercalcemia (Correct Answer)
B. Hyponatremia
C. Hyperkalemia
D. Hypokalemia

Explanation: ***Hypercalcemia*** - Long-term lithium therapy can lead to an increased risk of developing **primary hyperparathyroidism** (occurs in approximately 10% of chronic users), which subsequently causes hypercalcemia. - Lithium can affect the **set point of the calcium-sensing receptor** in the parathyroid glands, leading to inappropriate secretion of parathyroid hormone (PTH). - This is a **well-recognized complication** of chronic lithium therapy requiring monitoring of calcium and PTH levels. *Hyponatremia* - **Hyponatremia** is actually a frequently encountered electrolyte disturbance with lithium use, occurring through multiple mechanisms: - Lithium-induced **nephrogenic diabetes insipidus** leading to polyuria, polydipsia, and potential dehydration - Interaction with **thiazide diuretics** (which are sometimes used to treat lithium-induced polyuria, paradoxically) - SIADH-like effects in some patients - However, in the context of this examination question, **hypercalcemia due to hyperparathyroidism** is considered the characteristic chronic complication specifically linked to lithium's unique mechanism of action. *Hyperkalemia* - **Hyperkalemia** is not a commonly reported electrolyte imbalance specifically associated with lithium use. - While lithium can affect renal function and cause **renal tubular dysfunction**, this does not typically manifest as hyperkalemia. *Hypokalemia* - **Hypokalemia** is not typically associated with lithium use. - It is more commonly caused by diuretic use, vomiting, or diarrhea rather than lithium therapy directly.

Question 320: A patient was recently started on Fluphenazine. A few weeks later, he developed tremors, rigidity, bradykinesia, and excessive salivation. The first line of management for this patient is

A. Trihexyphenidyl (Correct Answer)
B. Amantadine
C. Selegiline (MAO-B inhibitor)
D. Pramipexole (Dopamine agonist)

Explanation: ***Trihexyphenidyl*** - The patient is exhibiting symptoms consistent with drug-induced **parkinsonism** caused by fluphenazine, an antipsychotic. - **Anticholinergics** like trihexyphenidyl are the **first-line treatment** for drug-induced parkinsonism by blocking muscarinic receptors in the striatum, restoring the dopamine-acetylcholine balance. *Selegiline (MAO-B inhibitor)* - Selegiline is used in Parkinson's disease to **increase dopamine levels** by inhibiting its breakdown, but it is not the first-line treatment for drug-induced parkinsonism where the issue is receptor blockade. - Its primary role is in **idiopathic Parkinson's disease** as an adjunctive therapy or for early symptom control, not for antipsychotic-induced extrapyramidal symptoms. *Amantadine* - Amantadine is an **NMDA receptor antagonist** and dopamine reuptake inhibitor used in Parkinson's disease. - While it has some efficacy in drug-induced parkinsonism, it is generally considered **second-line** after anticholinergics and is more effective for dyskinesia in idiopathic Parkinson's disease. *Pramipexole (Dopamine agonist)* - Dopamine agonists work by **directly stimulating dopamine receptors**, which would exacerbate the effects of D2 receptor blockade by fluphenazine. - They are used for **idiopathic Parkinson's disease** and restless legs syndrome, but are typically avoided in drug-induced parkinsonism.

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

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free