Drugs in Psychiatric Disorders — MCQs

Drugs in Psychiatric Disorders Indian Medical PG Practice Questions and MCQs

Question 271: Which of the following medications may be used in a child diagnosed with Attention Deficit Hyperactivity Disorder? I. Carbamazepine II. Methylphenidate III. Atomoxetine IV. Clonazepam Select the correct answer using the code given below :

A. I and III
B. I and IV
C. II and III (Correct Answer)
D. II and IV

Explanation: ***II and III*** - **Methylphenidate** is a first-line **CNS stimulant** that increases dopamine and norepinephrine in the prefrontal cortex, improving attention and reducing hyperactivity/impulsivity - **Atomoxetine** is a **selective norepinephrine reuptake inhibitor (SNRI)**, FDA-approved as a non-stimulant alternative for ADHD management - Both medications are **evidence-based treatments** for ADHD in children with proven efficacy in controlled trials *I and III* - **Carbamazepine** is an anticonvulsant used for epilepsy and bipolar disorder, **not indicated for ADHD** - While Atomoxetine is correct, pairing it with Carbamazepine makes this option incorrect *I and IV* - **Carbamazepine** has no role in ADHD management - **Clonazepam** is a benzodiazepine used for anxiety and seizures, **contraindicated in ADHD** as it causes sedation and may worsen attention deficits *II and IV* - While Methylphenidate is a core ADHD medication, **Clonazepam is inappropriate** for ADHD treatment - Benzodiazepines can impair cognitive function and exacerbate attention problems in ADHD patients

Question 272: A 35-year-old male patient presents to surgery emergency with painful erection for past 7 hours. He has a history of mood disorder and was recently prescribed a medication by treating psychiatrist. Which is the likely offending drug?

A. Venlafaxine
B. Tianeptine
C. Trazodone (Correct Answer)
D. Mirtazapine

Explanation: ***Trazodone*** - **Trazodone** is a commonly known antidepressant that can cause **priapism** as a side effect, especially at higher doses, due to its alpha-adrenergic blocking activity. [1] - The patient's presentation of a **painful erection lasting 7 hours** after starting a new psychiatric medication strongly points towards a drug-induced cause, for which trazodone is a well-established culprit. [1] *Venlafaxine* - **Venlafaxine** is an SNRI antidepressant that generally does not cause priapism as a recognized side effect. - Its adverse effect profile primarily includes nausea, insomnia, and sexual dysfunction (e.g., erectile dysfunction, anorgasmia), rather than prolonged erections. *Tianeptine* - **Tianeptine** is an atypical antidepressant that is not known to cause priapism. - It works by enhancing serotonin reuptake and is more commonly associated with side effects such as nausea, constipation, and dizziness. *Mirtazapine* - **Mirtazapine** is a tetracyclic antidepressant that works by blocking alpha-2 adrenergic receptors and certain serotonin receptors. - While it can cause sedation and weight gain, priapism is not a typical or recognized side effect of mirtazapine.

Question 273: Choose the correctly matched pairs regarding the drugs used in schizophrenia: 1. D2 antagonism: Reduces positive symptoms 2. 5HT2A antagonism: Reduces negative symptoms 3. 5HT1A agonism: Weight loss 4. Muscarinic antagonism: Reduces extrapyramidal symptoms

A. 1,4
B. 1,2,4
C. 1,2,3,4
D. 1,2 (Correct Answer)

Explanation: ***1,2*** - **D2 antagonism** is the primary mechanism by which antipsychotics reduce **positive symptoms** of schizophrenia, such as hallucinations and delusions. - **5HT2A antagonism** is a key mechanism of atypical antipsychotics contributing to the reduction of **negative symptoms** (e.g., apathy, anhedonia, flat affect) and cognitive deficits, while also reducing the risk of extrapyramidal symptoms. *1,2,3,4* - This option is incorrect because **5HT1A agonism** is not associated with **weight loss**. While 5HT1A partial agonism (as seen with aripiprazole and brexpiprazole) may improve negative symptoms, anxiety, and cognitive function, it does not directly cause weight loss. - Additionally, **muscarinic antagonism** does not reduce extrapyramidal symptoms as a primary mechanism. Rather, anticholinergic (muscarinic antagonist) drugs like benztropine are used to **treat** EPS after it occurs. The reduction of EPS in atypical antipsychotics primarily comes from 5HT2A antagonism and lower D2 binding affinity. *1,2,4* - This option is incorrect because **muscarinic antagonism** is not a mechanism that reduces EPS. Anticholinergic agents are used therapeutically to counteract EPS caused by dopamine blockade, but anticholinergic effects themselves do not prevent or reduce EPS. - The reduction of EPS with atypical antipsychotics is mainly due to **5HT2A antagonism** balancing dopaminergic blockade, selective limbic over striatal binding, and fast D2 dissociation kinetics. *1,4* - This option is incorrect because it omits **5HT2A antagonism**, which is crucial for reducing **negative symptoms** in schizophrenia. - It also incorrectly includes muscarinic antagonism as a mechanism that reduces EPS, when in reality anticholinergics are used to treat EPS rather than prevent it.

Question 274: A patient of schizophrenia is being treated with clozapine. For which rare but serious side effects should he be monitored?

A. Seizures
B. Agranulocytosis (Correct Answer)
C. Hepatomegaly
D. Renal bleed

Explanation: ***Agranulocytosis*** - **Agranulocytosis** is a severe and potentially fatal reduction in white blood cells (specifically neutrophils) that can occur with clozapine use [2, 3]. - This is the **rare but serious side effect** that requires mandatory monitoring, occurring in **0.8-2%** of patients. - Patients on clozapine require routine **complete blood count (CBC)** monitoring: **weekly for the first 6 months**, then biweekly for months 6-12, then monthly thereafter . - This is the primary reason clozapine has restricted use despite being the most effective antipsychotic for treatment-resistant schizophrenia. *Seizures* - While clozapine can lower the **seizure threshold** (especially at higher doses), seizures occur in **1-2%** of patients and are **dose-dependent** . - Seizures are a known side effect that warrants dosage adjustment, but they are **not as rare** as agranulocytosis and do not require the same intensive blood monitoring protocol. - Management involves dose reduction or adding anticonvulsants. *Hepatomegaly* - **Hepatic dysfunction** can occur with clozapine, but **hepatomegaly** (enlarged liver) itself is not one of its rare, life-threatening side effects requiring specific monitoring above other, more severe issues. - Liver enzyme elevation may be monitored, but this is not the primary "rare but serious" concern. *Renal bleed* - **Renal complications** or **renal bleeding** are not recognized as significant or specifically monitored rare side effects of clozapine. - Clozapine's major concerns primarily involve hematologic (agranulocytosis), cardiovascular (myocarditis), and metabolic systems.

Question 275: Which of the following is true about lithium?

A. It is also used for treatment of absence seizures
B. It is not teratogenic
C. It can cause fine postural tremors at therapeutic dosage (Correct Answer)
D. It is not absorbed from the gut

Explanation: ***It can cause fine postural tremors at therapeutic dosage*** - **Fine postural tremors** are a common and well-known side effect of lithium, even within its therapeutic range. - This side effect can be dose-dependent and may worsen with higher lithium concentrations. *It is also used for treatment of absence seizures* - Lithium is primarily used as a **mood stabilizer** for bipolar disorder and is not indicated for the treatment of **absence seizures**. - **Absence seizures** are typically treated with drugs like ethosuximide or valproate. *It is not teratogenic* - Lithium is known to be **teratogenic**, especially during the first trimester of pregnancy. - It is associated with an increased risk of **Ebstein's anomaly**, a congenital heart defect. *It is not absorbed from the gut* - Lithium is **rapidly and completely absorbed** from the gastrointestinal tract after oral administration. - Its absorption is not significantly affected by food, and peak plasma concentrations are usually reached within 1-3 hours.

Question 276: Venlafaxine comes under which class of drugs?

A. Monoamine oxidase inhibitors
B. Serotonin receptor antagonist
C. Selective serotonin reuptake inhibitor
D. Serotonin-norepinephrine reuptake inhibitor (SNRI) (Correct Answer)

Explanation: ***Serotonergic noradrenergic reuptake inhibitor*** - **Venlafaxine** is an antidepressant that works by inhibiting the reuptake of both **serotonin** and **norepinephrine**, making it a **Serotonin-Norepinephrine Reuptake Inhibitor (SNRI)**. - This dual mechanism contributes to its efficacy in treating **major depressive disorder**, **anxiety disorders**, and **neuropathic pain**. *Monoamine oxidase inhibitors* - **MAOIs** inhibit the enzyme **monoamine oxidase**, which metabolizes neurotransmitters like **serotonin**, **norepinephrine**, and **dopamine**. - They are associated with significant **food and drug interactions**, unlike venlafaxine. *Serotonin receptor antagonist* - These drugs *block* **serotonin receptors**, often used as **antiemetics** (e.g., ondansetron) or in some **antipsychotics**. - They do not primarily increase serotonin or norepinephrine levels via reuptake inhibition. *Selective serotonin reuptake inhibitor* - **SSRIs** (e.g., fluoxetine, sertraline) primarily inhibit the reuptake of **serotonin**, with minimal effect on other neurotransmitters. - While venlafaxine affects serotonin, it also significantly impacts norepinephrine, distinguishing it from SSRIs.

Question 277: Disulfiram is a type of:-

A. Anticraving therapy
B. Detoxification
C. Opioid management therapy
D. Aversion therapy (Correct Answer)

Explanation: **Aversion therapy** - **Disulfiram** works by inhibiting aldehyde dehydrogenase, leading to the accumulation of acetaldehyde when alcohol is consumed, which causes unpleasant symptoms like flushing, nausea, and vomiting. - This creates an **aversive reaction** to alcohol, which discourages further drinking, making it a form of aversion therapy. *Anticraving therapy* - While disulfiram can indirectly reduce cravings by making alcohol consumption unpleasant, its primary mechanism is not to directly modulate craving pathways in the brain. - Drugs like **naltrexone** or **acamprosate** are more commonly categorized as specific anticraving agents for alcohol dependence. *Detoxification* - **Detoxification** refers to the supervised withdrawal from a substance to manage acute withdrawal symptoms and stabilize the patient. - Disulfiram is used after detoxification to help maintain abstinence, not during the acute withdrawal phase. *Opioid management therapy* - **Opioid management therapy** involves medications like **methadone** or **buprenorphine** used to treat opioid dependence. - Disulfiram is specifically used for **alcohol use disorder** and has no role in managing opioid dependence.

Question 278: Which of the following drugs is specifically approved for the treatment of premature ejaculation?

A. Dapoxetine (Correct Answer)
B. Escitalopram
C. Citalopram
D. Chlorpromazine

Explanation: ***Dapoxetine*** - **Dapoxetine** is a **short-acting selective serotonin reuptake inhibitor (SSRI)** specifically approved for the on-demand treatment of **premature ejaculation (PE)**. - It works by delaying the ejaculatory reflex through its effect on serotonin transporters in the brain, thereby increasing the **intravaginal ejaculatory latency time (IELT)**. *Escitalopram* - **Escitalopram** is a **long-acting SSRI** primarily used for the treatment of **depression and anxiety disorders**. - While other SSRIs can be used off-label for PE, escitalopram's long half-life makes it less suitable for on-demand use, and it is not specifically approved for this indication. *Citalopram* - **Citalopram** is another **long-acting SSRI** used mainly for **depression and anxiety**, similar to escitalopram. - Its pharmacokinetic profile is not ideal for on-demand treatment of PE, and it carries a risk of QT prolongation, which further limits its use in this context. *Chlorpromazine* - **Chlorpromazine** is a **first-generation antipsychotic** used to treat **psychotic disorders** like schizophrenia, as well as severe nausea and vomiting. - It has no role in the direct treatment of premature ejaculation and its side effect profile, including sedation and extrapyramidal symptoms, makes it inappropriate for this condition.

Question 279: All are used in attention deficit hyperactivity disorder (ADHD) except:

A. Dextro-amphetamine
B. Methylphenidate
C. Phenobarbitone (Correct Answer)
D. Atomoxetine

Explanation: ***Phenobarbitone*** - **Phenobarbitone** (phenobarbital) is a **barbiturate** primarily used as an **anticonvulsant** and for sedation. - It works as a **CNS depressant** and would worsen, not improve, symptoms of ADHD, which include inattention, hyperactivity, and impulsivity. - **Not indicated** for ADHD management and may cause sedation, cognitive impairment, and paradoxical hyperactivity in children. *Dextro-amphetamine* - **Dextro-amphetamine** is a **stimulant medication** commonly used in ADHD. - It works by increasing levels of **dopamine** and **norepinephrine** in the brain, improving focus and reducing hyperactivity. - Approved for ADHD treatment in both children and adults. *Methylphenidate* - **Methylphenidate** is a **stimulant** widely prescribed for ADHD and considered a first-line treatment. - It acts as a **norepinephrine-dopamine reuptake inhibitor**, thereby increasing the availability of these neurotransmitters. - Available in immediate-release and extended-release formulations. *Atomoxetine* - **Atomoxetine** is a **non-stimulant** selective norepinephrine reuptake inhibitor (SNRI) used for ADHD. - It is particularly useful in patients who cannot tolerate stimulants or have comorbid anxiety disorders. - Preferred when there is concern about substance abuse or tic disorders.

Question 280: Which of the following drugs are used in the treatment of Attention-Deficit Hyperactivity Disorder (ADHD)?

A. Atomoxetine
B. Dexmethylphenidate
C. Methylphenidate
D. All of the options (Correct Answer)

Explanation: ***All of the options*** - **Atomoxetine**, **dexmethylphenidate**, and **methylphenidate** are all approved and commonly used medications for managing Attention-Deficit Hyperactivity Disorder (ADHD) [1]. - They represent different classes or formulations of drugs targeting neurotransmitter systems involved in ADHD. *Atomoxetine* - This is a **selective norepinephrine reuptake inhibitor** used for ADHD. - It is a **non-stimulant** option, often preferred for patients who do not tolerate stimulants or have co-existing anxiety disorders. *Dexmethylphenidate* - This is the **dextro-isomer** of methylphenidate, and it is a **central nervous system (CNS) stimulant** [1]. - It is known for its **potency** and faster onset of action due to only containing the active isomer. *Methylphenidate* - This is a **CNS stimulant** medication that works by blocking the reuptake of norepinephrine and dopamine [1]. - It is available in various formulations (short-acting, intermediate-acting, long-acting) to suit individual patient needs [1].

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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