Antidepressant Medications Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Antidepressant Medications. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Antidepressant Medications Indian Medical PG Question 1: An SSRI antidepressant, such as fluoxetine, will be prescribed for an adult patient. You should advise him or her that two of the most likely side effects or adverse responses that may eventually occur at therapeutic blood levels are which of the following?
- A. Sexual dysfunction and sleep disturbances (Correct Answer)
- B. Sexual dysfunction and nausea
- C. Headache and diarrhea
- D. Tremor and weight gain
Antidepressant Medications Explanation: ***Sexual dysfunction and sleep disturbances***
- **Sexual dysfunction** is one of the most common and persistent adverse effects of SSRIs, affecting 40-65% of patients and continuing throughout treatment at therapeutic levels [2], [3].
- **Sleep disturbances** (insomnia or altered sleep architecture) can persist during long-term SSRI therapy and are among the eventual side effects patients experience [1], [2], [3].
- Both effects are characteristic of chronic SSRI use and significantly impact patient compliance and quality of life.
*Sexual dysfunction and nausea*
- While **sexual dysfunction** is indeed very common and persistent, **nausea** is typically a transient side effect that occurs during the first 1-2 weeks of treatment and usually resolves with continued use [2].
- The question specifically asks about *eventual* occurrence at therapeutic levels over time, making nausea less appropriate as it is not a chronic issue.
*Tremor and weight gain*
- **Tremor** is not among the most common side effects of SSRIs and occurs less frequently than sexual dysfunction or sleep disturbances.
- **Weight gain** can occur with some SSRIs (particularly paroxetine), but fluoxetine is actually considered weight-neutral or may even cause weight loss in some patients, making this combination less likely for fluoxetine specifically [1].
*Headache and diarrhea*
- Both **headache** and **diarrhea** are common initial side effects when starting SSRIs but typically improve or resolve within the first few weeks of treatment [1].
- These are transient effects rather than eventual persistent side effects that characterize long-term therapeutic use.
Antidepressant Medications Indian Medical PG Question 2: A 45-year-old patient with a history of depression was initially being treated with sertraline, but his symptoms were not adequately controlled. His medication regimen was changed to include an MAO inhibitor and amitriptyline. Shortly after the change in medication, the patient developed agitation, seizures, hyperreflexia, and tremor. Which of the following is the most appropriate treatment for this patient?
- A. Cyproheptadine (Correct Answer)
- B. Lorazepam
- C. L-carnitine
- D. Leucovorin
- E. Dantrolene
Antidepressant Medications Explanation: ***Cyproheptadine***
- This patient exhibits symptoms of **serotonin syndrome** (agitation, seizures, hyperreflexia, tremor) due to the combination of an **MAO inhibitor** and **amitriptyline**.
- **Cyproheptadine** is a **serotonin antagonist** and is the most appropriate treatment for reversing the effects of serotonin syndrome.
- Treatment also includes discontinuing offending agents and supportive care.
*Lorazepam*
- **Lorazepam** is a **benzodiazepine** that can help manage agitation and seizures, but it does not address the underlying serotonin overstimulation.
- It would be used as an adjunct for symptom control, not as the primary treatment for serotonin syndrome.
*Dantrolene*
- **Dantrolene** is a **muscle relaxant** used for **neuroleptic malignant syndrome (NMS)** and **malignant hyperthermia**.
- While NMS and serotonin syndrome can have overlapping features (hyperthermia, rigidity), dantrolene is not indicated for serotonin syndrome.
- Cyproheptadine is the specific serotonin antagonist needed for this condition.
*L-carnitine*
- **L-carnitine** is a supplement often used for conditions like **carnitine deficiency** or certain **metabolic disorders**.
- It has no role in the treatment of serotonin syndrome.
*Leucovorin*
- **Leucovorin** (folinic acid) is used to **rescue bone marrow** from the toxic effects of **methotrexate** or to enhance the effects of **fluorouracil**.
- It is not indicated for the treatment of serotonin syndrome.
Antidepressant Medications Indian Medical PG Question 3: What is the mechanism of action of duloxetine?
- A. Selective serotonin reuptake inhibition
- B. Selective norepinephrine reuptake inhibition
- C. Inhibition of both serotonin and norepinephrine reuptake (Correct Answer)
- D. No effect on neurotransmitter reuptake
Antidepressant Medications Explanation: ***Inhibition of both serotonin and norepinephrine reuptake***
- **Duloxetine** is a **serotonin-norepinephrine reuptake inhibitor (SNRI)**, meaning it blocks the reuptake of both neurotransmitters, increasing their concentrations in the synaptic cleft [2].
- This dual action contributes to its efficacy in treating **depression**, **anxiety disorders**, and **neuropathic pain** [2], [3].
*Selective serotonin reuptake inhibition*
- This describes the mechanism of **SSRIs (Selective Serotonin Reuptake Inhibitors)**, such as fluoxetine or sertraline, which primarily target serotonin [1].
- Duloxetine's mechanism is broader, affecting both serotonin and norepinephrine [2].
*Selective norepinephrine reuptake inhibition*
- This mechanism is characteristic of medications like **atomoxetine**, used for ADHD, which primarily targets norepinephrine.
- Duloxetine has a dual action, not selective to norepinephrine alone.
*No effect on neurotransmitter reuptake*
- Medications with no effect on neurotransmitter reuptake would not typically be effective as antidepressants or treatments for neuropathic pain.
- Duloxetine's therapeutic effects are directly linked to its inhibition of reuptake for both serotonin and norepinephrine [2], [4].
Antidepressant Medications Indian Medical PG Question 4: A patient with nocturnal enuresis and depressive symptoms was started on an antidepressant. What is the drug?
- A. clomipramine
- B. sertraline
- C. amitriptyline
- D. imipramine (Correct Answer)
Antidepressant Medications Explanation: ***Imipramine*** - **Imipramine (Tofranil)** is a **tricyclic antidepressant (TCA)** [1] historically used for **nocturnal enuresis** due to its anticholinergic and alpha-adrenergic effects, which increase bladder capacity and sphincter tone. While it treats **depressive symptoms** [2], its use in enuresis has declined due to newer therapies with fewer side effects. *Clomipramine* - **Clomipramine (Anafranil)** is primarily used for **obsessive-compulsive disorder (OCD)** but also has antidepressant effects. While it shares some properties with imipramine as a TCA, it is **not the primary choice for nocturnal enuresis** and is more known for its serotonin reuptake inhibition. *Sertraline* - **Sertraline (Zoloft)** is a **selective serotonin reuptake inhibitor (SSRI)** commonly used for depression, anxiety disorders, and OCD. It **does not have a recognized role in treating nocturnal enuresis** and can sometimes even worsen urinary symptoms or cause nocturnal polyuria. *Amitriptyline* - **Amitriptyline (Elavil)** is a TCA effective for **depression**, **neuropathic pain**, and **migraine prophylaxis**. While it has strong anticholinergic properties that could theoretically affect bladder function, it is **not the preferred TCA for nocturnal enuresis**; imipramine has a more established history for this indication.
Antidepressant Medications Indian Medical PG Question 5: Acetazolamide is:
- A. Competitive and reversible carbonic anhydrase inhibitor (Correct Answer)
- B. Non-competitive and irreversible carbonic anhydrase inhibitor
- C. Non-competitive and reversible carbonic anhydrase inhibitor
- D. Competitive and irreversible carbonic anhydrase inhibitor
Antidepressant Medications Explanation: ***Competitive and reversible carbonic anhydrase inhibitor***
- Acetazolamide is a **competitive inhibitor** that binds directly to the **zinc ion in the active site** of carbonic anhydrase.
- It **competes with the natural substrate (CO2/HCO3-)** for binding to the active site, which is the hallmark of competitive inhibition.
- It is a **reversible inhibitor**, meaning it eventually dissociates from the enzyme and its effects are not permanent.
- As a sulfonamide derivative, it mimics the substrate and blocks the enzyme's catalytic activity temporarily.
*Competitive and irreversible carbonic anhydrase inhibitor*
- While acetazolamide is indeed a **competitive inhibitor**, it is **not irreversible**.
- An irreversible inhibitor forms a **permanent covalent bond** with the enzyme, which acetazolamide does not do.
- The drug's effects wear off as it is metabolized and excreted, demonstrating its reversible nature.
*Non-competitive and reversible carbonic anhydrase inhibitor*
- This option is incorrect because acetazolamide **does not bind to an allosteric site**.
- It binds directly to the **active site zinc ion**, making it a competitive inhibitor, not non-competitive.
- Non-competitive inhibitors bind to sites other than the active site and cannot be overcome by increasing substrate concentration.
*Non-competitive and irreversible carbonic anhydrase inhibitor*
- Acetazolamide is neither **non-competitive** nor **irreversible**.
- It binds to the **active site** (competitive mechanism) and its binding is **reversible**.
- This option combines two incorrect characteristics of the drug's mechanism of action.
Antidepressant Medications Indian Medical PG Question 6: 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
Antidepressant Medications 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.
Antidepressant Medications Indian Medical PG Question 7: Which of the following is a tricyclic antidepressant?
- A. Fluoxetine
- B. Citalopram
- C. Doxepin (Correct Answer)
- D. Venlafaxine
Antidepressant Medications Explanation: ***Doxepin***
- **Doxepin** is a **tricyclic antidepressant (TCA)** that inhibits the reuptake of **serotonin** and **norepinephrine**, and also has significant **histaminergic** and **cholinergic** blocking effects.
- TCAs, including doxepin, are commonly used for treating **depression**, **anxiety**, and certain pain conditions.
*Venlafaxine*
- **Venlafaxine** is a **serotonin-norepinephrine reuptake inhibitor (SNRI)**, not a tricyclic antidepressant.
- SNRIs selectively block the reuptake of both **serotonin** and **norepinephrine**, but lack the broad receptor affinity of TCAs.
*Fluoxetine*
- **Fluoxetine** is a **selective serotonin reuptake inhibitor (SSRI)**, which specifically targets serotonin reuptake.
- SSRIs are generally considered a first-line treatment for depression due to a more favorable side effect profile compared to TCAs.
*Citalopram*
- **Citalopram** is also a **selective serotonin reuptake inhibitor (SSRI)**, much like fluoxetine.
- It works by increasing the levels of **serotonin** in the brain by blocking its reuptake, differentiating it from tricyclic antidepressants.
Antidepressant Medications Indian Medical PG Question 8: Identify the false statement regarding suicide inhibition
- A. The binding of the enzyme to the substrate analogue is irreversible
- B. The inhibitor forms a product with the enzyme and the product inhibits it
- C. The inhibitor can bind with any site resulting in suicidal inhibition (Correct Answer)
- D. They are enzyme specific and used in rational drug design
Antidepressant Medications Explanation: ***The inhibitor can bind with any site resulting in suicidal inhibition***
- Suicide inhibition, also known as **mechanism-based inhibition**, is highly specific and requires the inhibitor to bind to the **active site** of the enzyme.
- The enzyme then catalyzes a transformation of the inhibitor into a **reactive intermediate** that irreversibly binds to the active site.
*The binding of the enzyme to the substrate analogue is irreversible*
- This statement is true; once the suicide inhibitor is metabolically activated by the enzyme, it forms a **covalent bond** with a residue in the active site.
- This irreversible binding permanently inactivates the enzyme.
*The inhibitor forms a product with the enzyme and the product inhibits it*
- This statement is true; the enzyme's catalytic action converts the inhibitor (a substrate analogue) into a **highly reactive compound**.
- This reactive product then binds covalently and irreversibly to the enzyme's **active site**, leading to its inactivation.
*They are enzyme specific and used in rational drug design*
- This statement is true; suicide inhibitors are designed to be highly specific for a particular enzyme, as they rely on that enzyme's catalytic mechanism for their activation.
- Their specificity and irreversible action make them valuable tools in **drug discovery** and **rational drug design**, allowing for targeted inactivation of disease-related enzymes.
Antidepressant Medications Indian Medical PG Question 9: A young male patient has been on 5 mg haloperidol for many days. For the last 4 days, he has developed inner restlessness and urges to move. What is the diagnosis?
- A. Akathisia (Correct Answer)
- B. Acute Dystonia
- C. Rabbit syndrome
- D. Tardive dyskinesia
Antidepressant Medications Explanation: ***Akathisia***
- This patient's symptoms of **inner restlessness** and an **urge to move** after several days on **haloperidol** are classic presentations of **akathisia**, a common extrapyramidal side effect of antipsychotics.
- Akathisia is a **motor restlessness** that can manifest as fidgeting, pacing, or an inability to sit still, often causing significant distress for the patient.
*Acute Dystonia*
- **Acute dystonia** typically presents as **sustained muscle contractions** leading to abnormal postures, such as **torticollis**, oculogyric crisis, or opisthotonos.
- It usually occurs within the **first few hours or days** of antipsychotic initiation, appearing earlier than the reported 4 days in this case, and its primary feature is involuntary muscle spasms, not a subjective feeling of restlessness.
*Rabbit syndrome*
- **Rabbit syndrome** is characterized by fine, rhythmic, **perioral tremors** resembling a rabbit chewing.
- This condition is a **late-onset extrapyramidal symptom**, similar to tardive dyskinesia, and does not involve the generalized inner restlessness described.
*Tardive dyskinesia*
- **Tardive dyskinesia** involves involuntary, repetitive movements, primarily of the **face, mouth, tongue**, and limbs, such as lip smacking, grimacing, or writhing.
- It is a **late-onset side effect** that typically develops after months or years of antipsychotic use,
not within 4 days.
Antidepressant Medications Indian Medical PG Question 10: A patient is experiencing subtle involuntary movements of his hands, feet, lips, and tongue. What is the expected response of these symptoms during the tapering of antipsychotic medication?
- A. It will resolve immediately after the medication is decreased.
- B. It will initially increase as the medication is decreased. (Correct Answer)
- C. It will remain the same.
- D. It will resolve in his hands but not in his feet.
Antidepressant Medications Explanation: ***It will initially increase as the medication is decreased.***
- The involuntary movements described are characteristic of **tardive dyskinesia**, a side effect of long-term antipsychotic use.
- When antipsychotic medication is tapered or discontinued, the **dopamine receptors**, which have been chronically blocked, become hypersensitive, leading to an initial worsening or unmasking of dyskinetic movements due to temporary dopamine overdrive.
*It will resolve immediately after the medication is decreased.*
- Tardive dyskinesia symptoms rarely resolve immediately upon antipsychotic reduction or discontinuation; instead, they often become **more pronounced** as receptor sensitivity changes.
- The withdrawal of the medication unmasks the underlying dopamine receptor hypersensitivity, leading to an initial increase rather than immediate resolution.
*It will remain the same.*
- The dynamic nature of dopamine receptor hypersensitivity means that symptoms of tardive dyskinesia are unlikely to remain stable during changes in antipsychotic dosage.
- **Dopamine receptor sensitivity** is altered by the change in medication levels, leading to a noticeable shift in symptom severity.
*It will resolve in his hands but not in his feet.*
- Tardive dyskinesia typically affects muscle groups globally, often including movements of the **face, trunk, and extremities**, rather than resolving in some areas and not others.
- The pathophysiology involving **widespread dopamine receptor changes** does not usually manifest with selective resolution in specific body parts.
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