Anxiolytics and Hypnotics — MCQs
Which of the following neurotransmitters is NOT suspected to be involved in the pathophysiology of schizophrenia?
Modafinil is approved by FDA for treatment of all except:
How do benzodiazepines exert their sedative effects?
Which of the following actions is NOT associated with tricyclic antidepressants?
Diazepam poisoning is treated by:
Drug of choice for night terrors:
Which of the following dependence-causing drugs is most commonly abused worldwide?
Clozapine is used in:
Which antipsychotic has anti-suicidal properties?
What is the drug of choice for a schizophrenic patient with poor oral absorption?
Anxiolytics and Hypnotics Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following neurotransmitters is NOT suspected to be involved in the pathophysiology of schizophrenia?
- A. Ascorbic acid (Correct Answer)
- B. Serotonin (5-HT)
- C. Norepinephrine
- D. Glutamate
Explanation: ***Ascorbic acid*** - **Ascorbic acid (Vitamin C)** is an important antioxidant and cofactor, but it is **not a neurotransmitter**. - While it may have neuroprotective roles, there is **no significant theory** suggesting ascorbic acid dysregulation is involved in the core pathophysiology of schizophrenia. - Unlike the other options, ascorbic acid is not part of any major neurotransmitter hypothesis of schizophrenia. *Serotonin (5-HT)* - The **serotonin hypothesis** of schizophrenia suggests an imbalance in serotonergic activity, particularly involving **5-HT2A receptors**. - Serotonin is targeted by **atypical antipsychotics** (e.g., risperidone, olanzapine) which block 5-HT2A receptors. - Serotonin dysregulation is believed to contribute to both **positive and negative symptoms** of schizophrenia. *Norepinephrine* - Dysregulation of **norepinephrine** has been implicated in the **cognitive and negative symptoms** of schizophrenia. - Alterations in noradrenergic systems contribute to deficits in **attention, working memory, and motivation** in affected individuals. - The prefrontal cortex noradrenergic system is particularly relevant to schizophrenia pathophysiology. *Glutamate* - The **NMDA receptor hypofunction hypothesis** is a major theory in schizophrenia pathophysiology. - **Glutamate** dysfunction, particularly involving NMDA receptors, can explain positive, negative, and cognitive symptoms. - NMDA receptor antagonists (like PCP and ketamine) can **induce psychotic symptoms** similar to schizophrenia, supporting this hypothesis.
Question 2: Modafinil is approved by FDA for treatment of all except:
- A. Narcolepsy
- B. Shift work sleep disorder (SWSD)
- C. Obstructive sleep apnea syndrome (OSAS)
- D. Lethargy in depression (Correct Answer)
Explanation: ***Lethargy in depression*** - Modafinil is **not FDA-approved** for treating lethargy or fatigue specifically in the context of depression. Its primary indications are for disorders of excessive daytime sleepiness. - While it may be used off-label in some cases for depression-related fatigue, it lacks formal FDA approval and specific efficacy data for this indication. *Narcolepsy* - Modafinil is **FDA-approved** as a wakefulness-promoting agent for the treatment of excessive daytime sleepiness associated with **narcolepsy**. - It helps reduce the frequency and severity of sleep attacks by promoting wakefulness through effects on **dopamine**, **norepinephrine**, and **histamine** systems in the brain. *Shift work sleep disorder (SWSD)* - Modafinil is **FDA-approved** to improve wakefulness in patients with excessive sleepiness associated with **shift work sleep disorder**. - It helps individuals working non-traditional hours (night shifts, rotating shifts) maintain alertness during their work periods. *Obstructive sleep apnea syndrome (OSAS)* - Modafinil is **FDA-approved** as an **adjunctive treatment** for residual excessive daytime sleepiness in patients with **obstructive sleep apnea/hypopnea syndrome (OSAHS)** who are receiving adequate treatment with CPAP. - It addresses persistent sleepiness that remains even after appropriate primary airway management.
Question 3: How do benzodiazepines exert their sedative effects?
- A. They enhance GABAergic transmission. (Correct Answer)
- B. They increase norepinephrine levels and enhance GABA transmission.
- C. They block dopamine receptors and enhance GABA transmission.
- D. They inhibit acetylcholine release and enhance GABA transmission.
Explanation: ***They enhance GABAergic transmission.*** - Benzodiazepines bind to a specific site on the **GABA-A receptor**, increasing its affinity for the **neurotransmitter GABA**. - This binding leads to an increased frequency of **chloride channel opening**, hyperpolarizing the neuron and making it less excitable, which produces sedative effects. *They increase norepinephrine levels and enhance GABA transmission.* - While benzodiazepines enhance GABA transmission, they do **not primarily increase norepinephrine levels**. - Medications that increase norepinephrine levels, such as certain antidepressants, typically have stimulating rather than sedative effects. *They block dopamine receptors and enhance GABA transmission.* - While benzodiazepines enhance GABA transmission, they do **not block dopamine receptors**. - Blocking dopamine receptors is the primary mechanism of action for many **antipsychotic medications**, which have different pharmacological profiles and side effects compared to benzodiazepines. *They inhibit acetylcholine release and enhance GABA transmission.* - While benzodiazepines enhance GABA transmission, they generally do **not directly inhibit acetylcholine release**. - Muscarinic acetylcholine receptor antagonists (anticholinergics) inhibit acetylcholine and can cause sedation, but this is a distinct mechanism from benzodiazepines.
Question 4: Which of the following actions is NOT associated with tricyclic antidepressants?
- A. Block 5-HT or NE reuptake
- B. Anticholinergic action
- C. MAO inhibition (Correct Answer)
- D. Causes sedation
Explanation: ***MAO inhibition*** - Tricyclic antidepressants (TCAs) primarily exert their effects by inhibiting the reuptake of **norepinephrine** and **serotonin**, not by inhibiting monoamine oxidase (MAO). - **MAO inhibitors** are a distinct class of antidepressants with a different mechanism of action and side effect profile. *Anticholinergic action* - Many TCAs have significant **anticholinergic effects**, blocking muscarinic receptors and leading to side effects like dry mouth, constipation, and blurred vision. - These effects contribute to the **adverse event profile** of TCAs, especially in elderly patients. *Block 5-HT or NE reuptake* - The primary mechanism of action of TCAs involves the **inhibition of serotonin (5-HT)** and **norepinephrine (NE) reuptake** into presynaptic neurons. - This action increases the concentration of these neurotransmitters in the **synaptic cleft**, thereby potentiating their effects. *Causes sedation* - TCAs frequently cause **sedation**, particularly the more histaminergic ones (e.g., amitriptyline, doxepin), due to their **histamine H1 receptor antagonism**. - This side effect can be beneficial for patients with insomnia but can be problematic for daytime functioning.
Question 5: Diazepam poisoning is treated by:
- A. Resins
- B. Hemofiltration
- C. Charcoal
- D. Flumazenil (Correct Answer)
Explanation: ***Flumazenil*** - **Flumazenil** is a **benzodiazepine receptor antagonist** that competitively binds to the benzodiazepine binding site on the GABA-A receptor, reversing the effects of diazepam. - It is used in cases of severe benzodiazepine overdose causing **respiratory depression** or **severe sedation**. *Resins* - **Resins**, such as **cholestyramine**, are typically used to bind toxins or drugs in the **gastrointestinal tract** that undergo enterohepatic recirculation. - They are generally not effective for reversing the central nervous system depression caused by a benzodiazepine overdose. *Hemofiltration* - **Hemofiltration** is a form of renal replacement therapy used to remove small and middle molecular weight substances from the blood. - While it can remove some drugs, **diazepam** is highly **lipophilic** and extensively **protein-bound**, making it poorly amenable to removal by hemofiltration. *Charcoal* - **Activated charcoal** is used to prevent the absorption of ingested toxins from the gastrointestinal tract. - It is effective when administered soon after ingestion but does not reverse the established effects of an absorbed drug like diazepam in an overdose situation.
Question 6: Drug of choice for night terrors:
- A. Tricyclic antidepressant
- B. Meprobamate
- C. Diazepam
- D. Clonazepam (Correct Answer)
Explanation: ***Clonazepam*** - **Clonazepam**, a benzodiazepine, is the **drug of choice** for night terrors due to its ability to suppress Stage 3 and 4 **slow-wave sleep**, where night terrors occur. - Its sedative and anxiolytic effects help to calm the patient and reduce the frequency and severity of these episodes. *Tricyclic antidepressant* - While some **tricyclic antidepressants** (TCAs) have sedative properties, they are generally not the first-line treatment for night terrors. - Their side effect profile and potential to alter other sleep stages make them less suitable than benzodiazepines for this specific parasomnia. *Meprobamate* - **Meprobamate** is an anxiolytic and sedative drug that is largely historical and has been replaced by safer and more effective alternatives like benzodiazepines. - It has a higher risk of dependence and side effects compared to modern treatments for sleep disorders. *Diazepam* - **Diazepam** is another benzodiazepine, but **clonazepam** is generally preferred for night terrors due to its longer half-life and specific efficacy in suppressing slow-wave sleep. - While diazepam could offer some relief, clonazepam is considered more effective for sustained management of this condition.
Question 7: Which of the following dependence-causing drugs is most commonly abused worldwide?
- A. Cannabis (Correct Answer)
- B. Heroin
- C. Amphetamine
- D. Cocaine
Explanation: ***Cannabis*** - **Cannabis** is the most widely cultivated and consumed illicit drug globally, with the highest prevalence of past-year use. - Its widespread availability, relatively lower perception of harm compared to other drugs, and varied forms of consumption (smoking, edibles) contribute to its extensive abuse. *Heroin* - **Heroin** is a highly addictive opioid that causes severe physical dependence and withdrawal symptoms, but its global prevalence is significantly lower than that of cannabis. - Its high cost, illicit nature, and significant health risks, including overdose, limit its abuse to a smaller, though critically affected, population. *Amphetamine* - **Amphetamines**, including methamphetamine, are potent central nervous system stimulants with a significant abuse potential, leading to psycho-behavioral and physical dependence. - While prevalent in certain regions and among specific populations, their overall global abuse statistics are lower than those for cannabis. *Cocaine* - **Cocaine** is a powerful stimulant derived from the coca plant, known for its strong psychological dependence and significant health consequences. - Its abuse is concentrated in specific geographical areas and demographic groups, making its global prevalence of abuse lower than that of cannabis.
Question 8: Clozapine is used in:
- A. Depression
- B. Resistant schizophrenia (Correct Answer)
- C. Mania
- D. Delirium
Explanation: **Explanation:** **Clozapine** is an atypical (second-generation) antipsychotic and is considered the **gold standard** for the management of **Treatment-Resistant Schizophrenia (TRS)**. 1. **Why Option B is Correct:** Resistance in schizophrenia is defined as a lack of satisfactory clinical improvement despite the use of adequate doses of at least two different antipsychotics (including one atypical) for a duration of 6–8 weeks each. Clozapine is uniquely effective in these cases due to its complex receptor profile (low D2 affinity, high 5-HT2A, D4, and alpha-adrenergic blockade). It is the only antipsychotic proven to reduce suicidal behavior in schizophrenic patients. 2. **Why Other Options are Incorrect:** * **A. Depression:** First-line treatments are SSRIs/SNRIs. While some atypicals (like Quetiapine or Aripiprazole) are used as adjuncts in resistant depression, Clozapine is not used due to its side-effect profile. * **C. Mania:** Acute mania is treated with Lithium, Valproate, or standard antipsychotics (e.g., Olanzapine, Risperidone). Clozapine is reserved only for ultra-resistant cases, not as a standard indication. * **D. Delirium:** Low-dose Haloperidol is the drug of choice. Clozapine is contraindicated in delirium because its strong anticholinergic properties can worsen the confusional state. **High-Yield Clinical Pearls for NEET-PG:** * **Agranulocytosis:** The most dreaded side effect (occurs in ~1%). Mandatory **WBC monitoring** is required (weekly for the first 6 months). * **Seizures:** Clozapine carries a dose-dependent risk of seizures. * **Sialorrhea:** Paradoxical hypersalivation is a common, bothersome side effect. * **Myocarditis:** A rare but fatal side effect; monitor for tachycardia and chest pain. * **Metabolic Syndrome:** High risk of weight gain and diabetes (similar to Olanzapine).
Question 9: Which antipsychotic has anti-suicidal properties?
- A. clozapine (Correct Answer)
- B. chlorpromazine
- C. aripiprazole
- D. amisulpride
Explanation: **Explanation:** **Clozapine** is the correct answer because it is the only antipsychotic with a specifically FDA-approved indication for reducing the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder. This anti-suicidal effect is independent of its primary antipsychotic action and is believed to be mediated by its unique modulation of serotonergic (5-HT2A) and noradrenergic systems, which helps reduce impulsivity and aggression. **Analysis of Incorrect Options:** * **B. Chlorpromazine:** A typical (first-generation) antipsychotic primarily used for acute psychosis. While it treats positive symptoms, it has no proven specific anti-suicidal properties and may even worsen depressive symptoms in some patients. * **C. Aripiprazole:** A partial dopamine agonist. While effective for mood stabilization and augmentation in depression, it does not carry a specific indication for suicide prevention. * **D. Amisulpride:** A substituted benzamide that is effective for both positive and negative symptoms of schizophrenia, but lacks evidence for a direct anti-suicidal effect. **High-Yield Clinical Pearls for NEET-PG:** * **The "Rule of Two":** There are two main drugs in psychiatry known for reducing suicide risk: **Clozapine** (in Schizophrenia) and **Lithium** (in Bipolar Disorder). * **Clozapine Monitoring:** Due to the risk of **agranulocytosis**, regular monitoring of Absolute Neutrophil Count (ANC) is mandatory. * **Other Side Effects:** Clozapine is associated with the highest risk of seizures (dose-dependent), sialorrhea (drooling), myocarditis, and metabolic syndrome among antipsychotics. * **Indication:** It remains the gold standard for **Treatment-Resistant Schizophrenia** (defined as failure of two adequate trials of other antipsychotics).
Question 10: What is the drug of choice for a schizophrenic patient with poor oral absorption?
- A. Haloperidol
- B. Fluphenazine
- C. Clozapine (Correct Answer)
- D. Olanzapine
Explanation: ### Explanation **Correct Option: C. Clozapine** The core concept here is the **pharmacokinetic profile** of antipsychotics. Clozapine is unique because it undergoes extensive first-pass metabolism, but more importantly, it is the only antipsychotic where **therapeutic drug monitoring (TDM)** is frequently used to overcome absorption issues or treatment resistance. In clinical scenarios involving "poor oral absorption" (often due to gastrointestinal issues or high first-pass effect), Clozapine remains the **Drug of Choice (DOC) for treatment-resistant schizophrenia**. While other drugs have parenteral formulations, Clozapine is the gold standard for patients who fail to respond to standard therapy, which often includes those with metabolic or absorption variations that render other oral medications ineffective. **Analysis of Incorrect Options:** * **A & B (Haloperidol & Fluphenazine):** These are typical antipsychotics. While they are available as long-acting decanoate injections (useful for poor *compliance*), they are not specifically indicated for poor *absorption* over Clozapine in a refractory context. * **D. Olanzapine:** An atypical antipsychotic similar to Clozapine but lacks the same level of efficacy in treatment-resistant cases. It is often a second-line choice but does not supersede Clozapine for complex absorption/resistance profiles. **High-Yield Clinical Pearls for NEET-PG:** * **Clozapine Indications:** Treatment-resistant schizophrenia (failed 2+ antipsychotics) and reducing suicidal behavior in schizophrenia. * **Adverse Effects:** Agranulocytosis (requires mandatory ANC monitoring), seizures (dose-dependent), myocarditis, and sialorrhea (hypersalivation). * **Lacks Extrapyramidal Symptoms (EPS):** Clozapine has the lowest risk of EPS and tardive dyskinesia among all antipsychotics. * **Metabolic Syndrome:** Both Clozapine and Olanzapine carry the highest risk of weight gain and diabetes.
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