Drugs in Psychiatric Disorders Practice Questions

Q: Which of the following antidepressant drugs is used in the treatment of nocturnal enuresis?

Imipramine. ***Imipramine*** - **Imipramine**, a **tricyclic antidepressant (TCA)**, is effective in treating nocturnal enuresis, particularly in children. - Its mechanism of action in this context is thought to involve anticholinergic effects, leading to **increased bladder capacity**, and alpha-adrenergic effects, causing **contraction of the internal urethral sphincter**. *Fluoxetine* - **Fluoxetine** is a **selective serotonin reuptake inhibitor (SSRI)** primarily used to treat depression, anxiety disorders, and obsessive-compulsive disorder. - It does not have a primary indication or established efficacy for the treatment of nocturnal enuresis. *Trazodone* - **Trazodone** is an **antidepressant** with sedative properties, often used for insomnia and depression. - While it modulates serotonin, it is not a first-line or established treatment for nocturnal enuresis. *Sertraline* - **Sertraline** is another **selective serotonin reuptake inhibitor (SSRI)** commonly prescribed for depression, anxiety, and panic disorder. - Like other SSRIs, it is not indicated for and has no significant role in the management of nocturnal enuresis.

Q: A patient stabilized on a selective serotonin reuptake inhibitor (SSRI) for depression may experience withdrawal symptoms when stopped. Which of the following drugs has the minimum risk of causing drug discontinuation symptoms?

Fluoxetine. ***Fluoxetine*** - **Fluoxetine** (Prozac) has the **longest half-life** among the SSRIs, leading to a much slower decrease in plasma concentration upon discontinuation. - This gradual reduction in drug levels lessens the severity and incidence of **discontinuation syndrome** symptoms. *Paroxetine* - **Paroxetine** (Paxil) has one of the **shortest half-lives** among the SSRIs, making it associated with a higher risk of severe discontinuation symptoms. - Its rapid elimination from the body leads to a quicker onset of withdrawal effects if stopped abruptly. *Sertraline* - **Sertraline** (Zoloft) has an intermediate half-life among SSRIs. - While generally better tolerated than paroxetine during discontinuation, it still carries a higher risk of withdrawal symptoms compared to fluoxetine. *Fluvoxamine* - **Fluvoxamine** (Luvox) has a relatively short half-life, similar to paroxetine, contributing to a higher risk of **discontinuation syndrome**. - It is particularly known for its potential for significant interactions due to potent **CYP450 inhibition**.

Q: Which of the following antipsychotic medications is most commonly used in depot preparation?

Haloperidol. ***Haloperidol*** - **Haloperidol decanoate** is the **most commonly used** depot antipsychotic preparation worldwide - It has been available since the **1970s** and remains the **gold standard** for long-acting injectable antipsychotics - Advantages include **long history of use**, **well-established efficacy**, **wide availability**, and **low cost** - Administered as **intramuscular injection** typically every **2-4 weeks** - Main limitation is higher risk of **extrapyramidal symptoms (EPS)** compared to second-generation depot antipsychotics *Risperidone* - **Risperidone** is available in depot formulations (**Risperdal Consta** - microspheres, **Risperdal Sustenna** - extended-release) - While widely used, it is **not the most common** depot preparation globally - Advantages include being a **second-generation antipsychotic** with lower EPS risk than haloperidol - More expensive than haloperidol decanoate, limiting its use in resource-constrained settings *Olanzapine* - **Olanzapine pamoate** is available as a **long-acting injectable** formulation - Requires mandatory **3-hour post-injection observation** due to risk of **post-injection delirium/sedation syndrome (PDSS)** - This monitoring requirement limits its practical use compared to other depot preparations - Less commonly used than haloperidol or risperidone depot formulations *Fluphenazine* - **Fluphenazine decanoate** is another first-generation antipsychotic available in depot form - Has been used since the 1960s-70s for maintenance therapy in schizophrenia - Similar to haloperidol in terms of EPS risk but less commonly used in current practice

Q: Which of the following is an atypical antipsychotic?

Clozapine. ***Clozapine*** - **Clozapine** is an **atypical antipsychotic** characterized by its efficacy in treating **refractory schizophrenia** and a lower risk of **extrapyramidal symptoms (EPS)** compared to typical antipsychotics. - Its mechanism involves antagonism of **dopamine D2** and **serotonin 5-HT2A** receptors, as well as several other receptor types. *Chlorpromazine* - **Chlorpromazine** is a **typical (first-generation) antipsychotic**, known for its strong **D2 blockade** and higher incidence of **extrapyramidal side effects**. - It was one of the first antipsychotics developed and is also used for its **antiemetic** properties. *Thiothixene* - **Thiothixene** is a **typical (first-generation) antipsychotic** that primarily acts by blocking **dopamine D2 receptors**. - It is associated with a higher risk of **extrapyramidal symptoms** and other side effects characteristic of typical antipsychotics. *Haloperidol* - **Haloperidol** is a **high-potency typical (first-generation) antipsychotic** with potent **D2 receptor antagonism**. - It is often used for acute psychosis and delirium but carries a significant risk of **extrapyramidal side effects** and **tardive dyskinesia**.

Q: Myocarditis is a side effect of which drug(s)?

clozapine. ***Clozapine*** - **Clozapine** is an atypical antipsychotic known to cause several serious side effects, including **myocarditis**, particularly during the initial weeks of treatment. - Patients on clozapine must be monitored for symptoms of myocarditis, such as **tachycardia**, **fever**, chest pain, and fatigue. *Aripiprazole* - **Aripiprazole** is generally considered to have a favorable cardiovascular safety profile compared to other antipsychotics. - While it can cause some cardiovascular side effects like **orthostatic hypotension**, **myocarditis** is not a commonly associated side effect. *Olanzapine* - **Olanzapine** is associated with metabolic side effects such as weight gain, dyslipidemia, and hyperglycemia. - Although it can rarely cause other cardiovascular issues like **QT prolongation**, **myocarditis** is not a characteristic adverse effect. *Chlorpromazine* - **Chlorpromazine** is a first-generation antipsychotic often linked to **QT prolongation** and **orthostatic hypotension**. - While it can have cardiovascular effects, **myocarditis** is not typically listed as one of its prominent or common adverse reactions.

Q: Which drug is commonly used to mitigate the side effects of haloperidol?

Benztropine. ***Correct Option C: Benztropine*** - **Benztropine** is an **anticholinergic medication** commonly used to treat **extrapyramidal symptoms (EPS)** induced by antipsychotics like haloperidol - EPS, such as **dystonia**, **akathisia**, and **parkinsonism**, occur due to dopaminergic blockade in the nigrostriatal pathway - Benztropine works by blocking muscarinic receptors, helping to restore the dopamine-acetylcholine balance in the basal ganglia *Incorrect Option A: Clozapine* - **Clozapine** is an **atypical antipsychotic** known for its effectiveness in **treatment-resistant schizophrenia** and a lower risk of EPS compared to typical antipsychotics - However, it is not used to mitigate existing side effects of other antipsychotics due to its unique side effect profile, including agranulocytosis and myocarditis - Clozapine is a therapeutic alternative, not a treatment for EPS *Incorrect Option B: Imipramine* - **Imipramine** is a **tricyclic antidepressant (TCA)** primarily used to treat **depression** and **anxiety disorders** - It does not have properties that would mitigate the extrapyramidal side effects induced by antipsychotics - TCAs have anticholinergic properties but are not used for EPS management *Incorrect Option D: Haloperidol* - **Haloperidol** is a **typical antipsychotic** itself, and it is the drug whose side effects (e.g., EPS) are being mitigated - Administering more haloperidol would exacerbate, not mitigate, its side effects - This is the causative agent, not the treatment

Q: Most common anomaly seen in a fetus of a mother taking lithium carbonate is:

Cardiac deformities. Detailed assessment of fetal risk indicates that the most significant and well-known teratogenic effect of **lithium carbonate** in utero is congenital **cardiac deformities**, particularly **Ebstein's anomaly** [2]. **Ebstein's anomaly** involves the downward displacement of the tricuspid valve, leading to tricuspid regurgitation and right heart failure [2]. *Limb reduction* - **Limb reduction defects** are typically associated with medications like **thalidomide** or vascular disruptions, not commonly with lithium exposure. - While various drug exposures can cause limb abnormalities, lithium's primary teratogenic risk lies elsewhere. *Neural tube defect* - **Neural tube defects (NTDs)** like spina bifida and anencephaly are most commonly associated with **folate deficiency** and certain antiepileptic drugs like valproic acid [1]. - Lithium has no established association with an increased risk of neural tube defects. *Genitourinary deformity* - While some medications can affect genitourinary development, **lithium carbonate** is not primarily linked to genitourinary deformities. - Its teratogenic effects are predominantly on the cardiovascular system.

Q: Which of the following antipsychotics is a partial D2 agonist?

Aripiprazole. Aripiprazole - Aripiprazole is a D2 partial agonist [1][3], meaning it acts as an agonist in areas with low dopamine and an antagonist in areas with high dopamine [3]. - This unique mechanism helps to stabilize dopamine activity, leading to fewer extrapyramidal symptoms and hyperprolactinemia compared to typical antipsychotics. Clozapine - Clozapine is a D2 antagonist with a high affinity for D4 receptors and potent antagonism of 5-HT2A receptors; it is known for its efficacy in treatment-resistant schizophrenia [2]. - It carries a risk of severe side effects such as agranulocytosis [2] and myocarditis, requiring regular blood monitoring. Quetiapine - Quetiapine is primarily a D2 antagonist with significant antagonism at histamine H1 and alpha-1 adrenergic receptors, contributing to its sedative and orthostatic hypotensive effects. - It is known for its relatively low risk of extrapyramidal symptoms due to its rapid dissociation from D2 receptors. Ziprasidone - Ziprasidone is a D2 antagonist and a serotonin 5-HT1A agonist and 5-HT2C antagonist, contributing to its antidepressant and anti-anxiety effects. - It is associated with a risk of QTc prolongation, which necessitates cardiac monitoring in susceptible patients.

Q: Which of the following antidepressants is least likely to have sexual side effects?

Mirtazapine. ***Mirtazapine*** - **Mirtazapine** is an atypical antidepressant (NaSSA - Noradrenergic and Specific Serotonergic Antidepressant) that works by blocking alpha-2 adrenergic receptors, enhancing serotonin and norepinephrine release [1]. - It has the **lowest incidence of sexual side effects** among antidepressants because it blocks 5-HT2 and 5-HT3 receptors while avoiding significant 5-HT1A stimulation, which is responsible for sexual dysfunction with SSRIs [1]. - It may even **improve libido** in some cases due to its unique receptor profile and histamine antagonism that can enhance sleep quality. *Amitriptyline* - **Amitriptyline** is a tricyclic antidepressant (TCA) with broad receptor actions, including anticholinergic and antihistaminic effects. - TCAs like amitriptyline can cause **sexual dysfunction** (including erectile dysfunction and decreased libido) due to their anticholinergic properties and effects on multiple neurotransmitter systems, though typically less severe than SSRIs. *Fluoxetine* - **Fluoxetine** is a selective serotonin reuptake inhibitor (SSRI), and while effective for depression, it is associated with a **high incidence of sexual side effects** (30-70% of patients) [2]. - These side effects include **decreased libido**, **anorgasmia**, and **erectile dysfunction**, caused by increased serotonergic activity at 5-HT2 receptors in areas regulating sexual function [2]. *Venlafaxine* - **Venlafaxine** is a serotonin-norepinephrine reuptake inhibitor (SNRI), increasing both serotonin and norepinephrine levels in the brain [1]. - Like SSRIs, SNRIs such as venlafaxine frequently cause **sexual dysfunction**, with common complaints including reduced libido and difficulty achieving orgasm due to enhanced serotonergic neurotransmission [1].

Q: Which is the mood stabilizer with a narrow therapeutic index?

lithium. Correct Option: Lithium - Lithium has a narrow therapeutic index, meaning there is a small difference between therapeutic and toxic doses (therapeutic range: 0.6-1.2 mEq/L; toxic level: >1.5 mEq/L) [1] - This narrow therapeutic window necessitates frequent monitoring of serum lithium levels and careful dosage adjustments to prevent toxicity while maintaining efficacy in mood stabilization [2] - Common signs of lithium toxicity include tremor, confusion, ataxia, and in severe cases, seizures and renal failure Incorrect Option: Valproate - While valproate is an effective mood stabilizer, its therapeutic index is wider compared to lithium, making it generally safer with less stringent monitoring requirements for toxicity [4] - It's associated with adverse effects like hepatotoxicity and pancreatitis, but acute toxicity from minor dose variations is less common than with lithium Incorrect Option: Carbamazepine - Carbamazepine is an anticonvulsant and mood stabilizer with a wider therapeutic index than lithium, though it requires monitoring for drug interactions and hematologic effects (agranulocytosis, aplastic anemia) [3] - Common side effects include dizziness, ataxia, and hyponatremia, but the risk of severe toxicity from minor dose changes is significantly lower than with lithium [3] Incorrect Option: Lamotrigine - Lamotrigine is a mood stabilizer used for bipolar disorder with a relatively wide therapeutic index, especially when compared to lithium - The most concerning side effect is Stevens-Johnson syndrome, a rare but serious skin rash, which risk is increased by rapid dose escalation; requires slow titration

Question 1

Which of the following antidepressant drugs is used in the treatment of nocturnal enuresis?

Accepted Answer

Imipramine

Answer

Fluoxetine

Answer

Trazodone

Answer

Sertraline

Question 2

A patient stabilized on a selective serotonin reuptake inhibitor (SSRI) for depression may experience withdrawal symptoms when stopped. Which of the following drugs has the minimum risk of causing drug discontinuation symptoms?

Accepted Answer

Fluoxetine

Answer

Paroxetine

Answer

Fluvoxamine

Answer

Sertraline

Question 3

Which of the following antipsychotic medications is most commonly used in depot preparation?

Accepted Answer

Haloperidol

Answer

Olanzapine

Answer

Fluphenazine

Answer

Risperidone

Question 4

Which of the following is an atypical antipsychotic?

Accepted Answer

Clozapine

Answer

Chlorpromazine

Answer

Thiothixene

Answer

Haloperidol

Question 5

Myocarditis is a side effect of which drug(s)?

Accepted Answer

clozapine

Answer

aripiprazole

Answer

olanzapine

Answer

chlorpromazine

Question 6

Which drug is commonly used to mitigate the side effects of haloperidol?

Accepted Answer

Benztropine

Answer

Clozapine

Answer

Imipramine

Answer

Haloperidol

Question 7

Most common anomaly seen in a fetus of a mother taking lithium carbonate is:

Accepted Answer

Cardiac deformities

Answer

Limb reduction

Answer

Neural tube defect

Answer

Genitourinary deformity

Question 8

Which of the following antipsychotics is a partial D2 agonist?

Accepted Answer

Aripiprazole

Answer

Clozapine

Answer

Quetiapine

Answer

Ziprasidone

Question 9

Which of the following antidepressants is least likely to have sexual side effects?

Accepted Answer

Mirtazapine

Answer

Amitriptyline

Answer

Fluoxetine

Answer

Venlafaxine

Question 10

Which is the mood stabilizer with a narrow therapeutic index?

Accepted Answer

lithium

Answer

valproate

Answer

lamotrigine

Answer

carbamazepine

Drugs in Psychiatric Disorders — MCQs

Drugs in Psychiatric Disorders — MCQs

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