Psychopharmacology Practice Questions

Q: Which second-generation antipsychotic functions as a first-generation antipsychotic in large doses?

Risperidone. **Explanation:** **Risperidone** is a second-generation (atypical) antipsychotic that exhibits a unique dose-dependent pharmacological profile [1]. At standard therapeutic doses (2–6 mg/day), it acts as a serotonin-dopamine antagonist (SDA), blocking 5-HT2A receptors more than D2 receptors. This balance reduces extrapyramidal side effects (EPS). However, at **high doses (>6–8 mg/day)**, its D2 receptor occupancy increases significantly, exceeding the 80% threshold. At this level, it behaves like a **first-generation (typical) antipsychotic**, leading to a high incidence of EPS and hyperprolactinemia. **Analysis of Incorrect Options:** * **A. Clozapine:** The "gold standard" for treatment-resistant schizophrenia. It has very low D2 affinity and high 5-HT2A/D4 affinity [1]; it almost never causes EPS, regardless of the dose. * **B. Quetiapine:** Known for "rapid dissociation" from D2 receptors. Even at high doses, it maintains a low risk of EPS, making it preferred in Parkinson’s disease patients with psychosis [2]. * **D. Lurasidone:** An atypical antipsychotic with potent 5-HT7 antagonism. While it can cause akathisia, it does not typically transition into a "first-generation" profile in the same dose-dependent manner as Risperidone. **NEET-PG High-Yield Pearls:** * **Hyperprolactinemia:** Among atypicals, Risperidone is the most notorious for causing elevated prolactin (due to strong D2 blockade in the tuberoinfundibular pathway). * **Active Metabolite:** Risperidone is metabolized to **Paliperidone** (9-hydroxyrisperidone) [1]. * **Aripiprazole:** Known as a "Dopamine System Stabilizer" (Partial D2 agonist) [1]. * **Olanzapine:** Associated with the highest risk of metabolic syndrome (weight gain, dyslipidemia) [1].

Q: Which of the following is an absolute contraindication for the use of lithium?

Renal failure. **Explanation:** **Lithium** is the gold standard mood stabilizer for Bipolar Affective Disorder (BPAD). Understanding its pharmacokinetics is crucial for NEET-PG: Lithium is a monovalent cation that is **exclusively excreted by the kidneys** and is not metabolized by the liver. 1. **Why Renal Failure is the Correct Answer:** Since Lithium is handled by the kidneys similarly to sodium (reabsorbed in the proximal tubule), any impairment in renal function leads to a drastic decrease in clearance. This results in rapid accumulation and **Lithium Toxicity**, which can be fatal or lead to permanent neurological damage (SILDCOR syndrome). Therefore, significant renal failure is an **absolute contraindication**. 2. **Analysis of Incorrect Options:** * **Glaucoma:** Unlike tricyclic antidepressants (TCAs) or antipsychotics with anticholinergic properties, Lithium does not significantly affect intraocular pressure. It is safe to use in glaucoma. * **Epilepsy:** Lithium is not contraindicated in epilepsy. While it can lower the seizure threshold at toxic levels, it is generally safe at therapeutic levels. In fact, some studies suggest it may have mild anticonvulsant properties. * **Angina:** While Lithium can cause EKG changes (like T-wave flattening/inversion), it is not an absolute contraindication for stable angina. However, it should be used with caution in patients with sick sinus syndrome. **High-Yield Clinical Pearls for NEET-PG:** * **Teratogenicity:** Causes **Ebstein’s Anomaly** (tricuspid valve displacement) if taken in the 1st trimester. * **Therapeutic Index:** Very narrow (0.6–1.2 mEq/L). Toxicity starts >1.5 mEq/L. * **Drug Interactions:** **NSAIDs, Thiazides, and ACE inhibitors** increase Lithium levels by decreasing renal clearance (High-yield mnemonic: **"NAT"**). * **Side Effects:** Nephrogenic Diabetes Insipidus, Hypothyroidism, and Fine Tremors.

Q: Which of the following hormones is used in the adjuvant treatment of depression?

Levothyroxine. **Explanation:** **Levothyroxine (T4)** is the correct answer because thyroid hormones play a crucial role in modulating neurotransmitter systems (serotonin and norepinephrine) in the brain. In clinical psychiatry, T4 (and sometimes T3/Liothyronine) is used as an **augmentation strategy** for patients with Treatment-Resistant Depression (TRD), even in those who are euthyroid. It enhances the clinical response to standard antidepressants like SSRIs or TCAs by accelerating the onset of action and improving overall efficacy. **Analysis of Incorrect Options:** * **Progesterone (A):** While hormonal fluctuations (like those in postpartum or premenstrual periods) affect mood, progesterone is not a standard adjuvant for clinical depression. In fact, high levels of certain progesterone metabolites can sometimes induce depressive symptoms or sedation. * **Cortisol (B) & ACTH (C):** Elevated levels of cortisol and ACTH are actually associated with the *pathophysiology* of depression (Hypercortisolemia). Chronic activation of the HPA axis is a hallmark of melancholic depression; therefore, administering these would likely worsen the condition rather than treat it. **Clinical Pearls for NEET-PG:** * **T3 vs. T4:** While T4 is mentioned here, **Liothyronine (T3)** is historically more common in research for rapid augmentation due to its direct action on brain receptors. * **Other Augmentation Agents:** Common NEET-PG favorites for TRD augmentation include **Lithium** (most evidence), **Atypical Antipsychotics** (e.g., Aripiprazole, Quetiapine), and **Ketamine/Esketamine**. * **L-Methylfolate:** Another metabolic adjuvant used to enhance monoamine synthesis in depression.

Q: What is the prophylactic plasma concentration range of lithium in mEq that is generally NOT included?

1.0 mEq. **Explanation:** Lithium is the gold standard mood stabilizer for Bipolar Affective Disorder (BPAD). It has a **narrow therapeutic index**, meaning the difference between a therapeutic dose and a toxic dose is very small. Consequently, monitoring serum lithium levels is mandatory. **Why 1.0 mEq is the correct answer:** The therapeutic window for lithium is divided into two distinct phases: 1. **Acute Manic Episode:** 0.8 to 1.2 mEq/L (up to 1.5 mEq/L in some guidelines). 2. **Prophylaxis (Maintenance):** **0.6 to 0.8 mEq/L.** While 1.0 mEq/L is within the therapeutic range for an *acute* episode, it is generally considered too high for long-term prophylaxis due to the increased risk of renal and thyroid toxicity. Therefore, it is not included in the standard prophylactic range. **Analysis of Incorrect Options:** * **A (0.5 mEq):** Often considered the lower threshold for maintenance. While 0.6 is ideal, some patients are maintained at 0.5 mEq/L to minimize side effects. * **B & C (0.8 & 0.6 mEq):** These represent the classic "sweet spot" for prophylaxis. Maintaining levels within this range effectively prevents relapse while minimizing long-term organ damage. **High-Yield Clinical Pearls for NEET-PG:** * **Sampling Time:** Serum levels should be checked **12 hours** after the last dose (Trough level). * **Steady State:** Achieved in **5 days** (5 half-lives). * **Toxicity:** Levels **>1.5 mEq/L** are toxic; **>2.0 mEq/L** require urgent intervention; **>4.0 mEq/L** usually require hemodialysis. * **Teratogenicity:** Ebstein’s Anomaly (tricuspid valve displacement). * **Drug Interactions:** Thiazides, NSAIDs, and ACE inhibitors increase lithium levels (Decreased clearance).

Q: A 40-year-old man with a psychiatric illness, on medication for the past two weeks, suddenly develops marked rigidity, immobility, fever, fluctuating blood pressure, and heart rate. What is the most likely diagnosis?

Malignant neuroleptic syndrome. **Explanation:** The clinical presentation of **marked rigidity** ("lead-pipe" rigidity), **autonomic instability** (fluctuating BP and heart rate), **hyperpyrexia** (fever), and altered mental status (immobility/stupor) in a patient recently started on antipsychotics is a classic description of **Neuroleptic Malignant Syndrome (NMS)**. **1. Why the Correct Answer is Right:** NMS is a life-threatening idiosyncratic reaction to dopamine antagonists (typically first-generation antipsychotics like Haloperidol). It usually occurs within the first two weeks of treatment. The underlying mechanism is a massive **blockade of D2 receptors** in the nigrostriatal pathway (causing rigidity) and the hypothalamus (causing thermoregulatory failure/fever). **2. Why Incorrect Options are Wrong:** * **Akathisia:** Presents as subjective motor restlessness (inability to sit still). It does not involve fever or autonomic instability. * **Parkinsonism:** Characterized by tremors, bradykinesia, and cogwheel rigidity. While it involves rigidity, it lacks the life-threatening systemic features like high fever and tachycardia seen here. * **Catatonic Schizophrenia:** While it features immobility and rigidity (waxy flexibility), it is a primary psychiatric state and typically does not present with acute autonomic instability or high-grade fever unless complicated by "Lethal Catatonia." **3. NEET-PG High-Yield Pearls:** * **Key Lab Finding:** Significantly elevated **Creatine Phosphokinase (CPK)** levels due to muscle necrosis (rhabdomyolysis). * **Treatment of Choice:** Immediate drug discontinuation, aggressive cooling, and pharmacological intervention with **Dantrolene** (muscle relaxant) or **Bromocriptine** (D2 agonist). * **Mnemonic (FEVER):** **F**ever, **E**ncephalopathy, **V**itals unstable, **E**levated CPK, **R**igidity.

Q: Memory disturbance following electroconvulsive therapy (ECT) typically resolves within what timeframe?

A few weeks to a few months. **Explanation:** Memory impairment is the most common side effect of Electroconvulsive Therapy (ECT). The correct answer is **B (A few weeks to a few months)** because while acute cognitive deficits appear immediately after treatment, they are transient. **1. Why Option B is Correct:** ECT-induced memory loss typically involves two types: **Anterograde amnesia** (difficulty forming new memories), which usually resolves within 1–2 weeks post-treatment, and **Retrograde amnesia** (loss of past memories), which takes longer. Most patients return to their cognitive baseline within **1 to 6 months** after the final session. Long-term follow-up studies show that objective memory performance often improves beyond baseline levels as the underlying depression resolves. **2. Why Other Options are Incorrect:** * **Option A:** A few days is too short; while the post-ictal confusion clears in hours, the formal memory deficits persist longer. * **Option C & D:** While some patients subjectively report "gaps" in their memory for events surrounding the treatment period (permanent focal retrograde amnesia), global memory disturbance lasting years or being permanent is not the clinical norm and contradicts standard psychiatric data. **High-Yield Clinical Pearls for NEET-PG:** * **Type of ECT:** Bilateral ECT causes more memory impairment than Unilateral ECT. * **Electrode Placement:** Brief-pulse stimuli and Right Unilateral (RUL) placement (d'Elia placement) are used to minimize cognitive side effects. * **Pre-medication:** Atropine or Glycopyrrolate is used to prevent vagal bradycardia; Methohexital (gold standard) or Propofol is used for anesthesia; Succinylcholine is the muscle relaxant of choice. * **Mortality:** Extremely low (approx. 0.002% per treatment), usually due to cardiovascular complications.

Q: Which antidepressant is best for a patient with hypotension and cardiac disease?

Mianserin. **Explanation:** The correct answer is **Mianserin**. **Why Mianserin is the correct choice:** Mianserin is a tetracyclic antidepressant (TeCA) that acts as an alpha-2 adrenergic receptor antagonist. Unlike Tricyclic Antidepressants (TCAs), Mianserin is notably **devoid of anticholinergic effects** and has **minimal cardiovascular toxicity**. It does not inhibit the reuptake of norepinephrine to a significant degree at the cardiac level and does not cause orthostatic hypotension or conduction delays. This makes it one of the safest options for elderly patients or those with pre-existing cardiac disease and hypotension. **Analysis of Incorrect Options:** * **Venlafaxine & Duloxetine (SNRIs):** These agents inhibit the reuptake of norepinephrine. A common side effect, especially with Venlafaxine, is a **dose-dependent increase in blood pressure** (hypertension) and heart rate, making them less ideal for unstable cardiac patients. * **Citalopram (SSRI):** While SSRIs are generally cardiac-safe, Citalopram is specifically associated with **dose-dependent QTc interval prolongation**. In patients with structural cardiac disease, this increases the risk of fatal arrhythmias like Torsades de Pointes. **NEET-PG High-Yield Pearls:** * **Mianserin vs. Mirtazapine:** Both are alpha-2 antagonists. Mianserin is associated with a rare risk of **agranulocytosis** (requires CBC monitoring), whereas Mirtazapine is known for weight gain and sedation. * **Drug of Choice:** For a post-Myocardial Infarction (MI) patient with depression, **Sertraline** is often considered the gold standard due to its extensive safety data. * **Avoid TCAs:** In cardiac patients, TCAs are contraindicated as they are "quinidine-like" and cause PR/QT prolongation and orthostatic hypotension.

Q: A patient with depression is being treated with chlorpromazine, but auditory hallucinations persist. Which of the following would be the most appropriate next medication to consider?

Clozapine. **Explanation:** The core clinical challenge in this scenario is **Treatment-Resistant Psychosis** (or persistent positive symptoms) despite the use of a conventional antipsychotic (Chlorpromazine). **Why Clozapine is the Correct Answer:** Clozapine is the "gold standard" for treatment-resistant schizophrenia and persistent psychotic symptoms. It is indicated when a patient fails to respond to at least two different antipsychotic trials of adequate dose and duration. Unlike typical antipsychotics that primarily block $D_2$ receptors, Clozapine has a unique profile with high affinity for $D_4$ and $5-HT_{2A}$ receptors and low $D_2$ occupancy, making it effective where others fail. **Analysis of Incorrect Options:** * **Haloperidol:** This is a high-potency typical antipsychotic. Switching from one typical antipsychotic (Chlorpromazine) to another (Haloperidol) is unlikely to resolve symptoms if the patient is non-responsive to the class. * **Sulpiride:** A selective $D_2$ and $D_3$ receptor antagonist. While it has fewer extrapyramidal side effects, it does not possess the superior efficacy of Clozapine for resistant cases. * **Tianeptine:** This is an atypical antidepressant (SSRE). While the patient has depression, the primary issue described is the persistence of **auditory hallucinations**, which requires an antipsychotic adjustment, not an antidepressant. **High-Yield NEET-PG Pearls:** * **Clozapine Monitoring:** Mandatory weekly WBC/ANC monitoring for the first 6 months due to the risk of **Agranulocytosis** (1%). * **Side Effects:** Most common is **Sialorrhea** (drooling); most serious is **Seizures** (dose-dependent) and **Myocarditis**. * **Unique Benefit:** Clozapine is the only antipsychotic proven to reduce **suicidal behavior** in schizophrenia.

Q: What is the normal therapeutic level of Lithium?

0.7 to 1.1 mEq/lit. **Explanation:** Lithium is the gold-standard mood stabilizer used for the treatment of Bipolar Affective Disorder (BPAD). It has a **narrow therapeutic index**, meaning the margin between a therapeutic dose and a toxic dose is very slim, necessitating Therapeutic Drug Monitoring (TDM). 1. **Why Option B is Correct:** The standard therapeutic range for maintaining a patient in an acute manic episode is generally **0.8 to 1.2 mEq/L**, while the maintenance range for prophylaxis is **0.6 to 1.0 mEq/L**. Option B (0.7 to 1.1 mEq/L) most accurately captures the window required to achieve clinical efficacy while minimizing the risk of toxicity. 2. **Why Other Options are Incorrect:** * **Option A (0.5–0.7):** This is often considered sub-therapeutic for acute mania, though some elderly patients may be maintained at the lower end of this range. * **Option C (0.1–0.3):** These levels are clinically insignificant and will not provide a mood-stabilizing effect. * **Option D (1.5–2.0):** This range indicates **Lithium Toxicity**. Mild to moderate toxicity symptoms (tremors, vomiting, diarrhea) typically begin above 1.5 mEq/L. **High-Yield Clinical Pearls for NEET-PG:** * **Sampling Time:** Blood for TDM should be drawn **12 hours after the last dose** (Steady-state is reached in 4–5 days). * **Toxicity Thresholds:** >1.5 mEq/L (Mild/Moderate); >2.0 mEq/L (Severe); >3.5 mEq/L (Life-threatening; requires Hemodialysis). * **Side Effects:** Ebstein’s anomaly (teratogenic), Nephrogenic Diabetes Insipidus, Hypothyroidism, and fine tremors. * **Drug Interactions:** Thiazides, NSAIDs, and ACE inhibitors increase Lithium levels (Decreased clearance).

Question 1

Which second-generation antipsychotic functions as a first-generation antipsychotic in large doses?

Accepted Answer

Risperidone

Answer

Clozapine

Answer

Quetiapine

Answer

Lurasidone

Question 2

Which of the following is an absolute contraindication for the use of lithium?

Accepted Answer

Renal failure

Answer

Glaucoma

Answer

Epilepsy

Answer

Angina

Question 3

Which of the following hormones is used in the adjuvant treatment of depression?

Accepted Answer

Levothyroxine

Answer

Progesterone

Answer

Cortisol

Answer

ACTH

Question 4

What is the prophylactic plasma concentration range of lithium in mEq that is generally NOT included?

Accepted Answer

1.0 mEq

Answer

0.5 mEq

Answer

0.8 mEq

Answer

0.6 mEq

Question 5

At what serum lithium levels is permanent cerebellar damage typically observed?

Accepted Answer

>3 mEq/L

Answer

1-1.5 mEq/L

Answer

>2 mEq/L

Answer

>4 mEq/L

Question 6

A 40-year-old man with a psychiatric illness, on medication for the past two weeks, suddenly develops marked rigidity, immobility, fever, fluctuating blood pressure, and heart rate. What is the most likely diagnosis?

Accepted Answer

Malignant neuroleptic syndrome

Answer

Akathisia

Answer

Parkinsonism

Answer

Catatonic schizophrenia

Question 7

Memory disturbance following electroconvulsive therapy (ECT) typically resolves within what timeframe?

Accepted Answer

A few weeks to a few months

Answer

A few days to a few weeks

Answer

A few months to a few years

Answer

Permanent

Question 8

Which antidepressant is best for a patient with hypotension and cardiac disease?

Accepted Answer

Mianserin

Answer

Venlafaxine

Answer

Duloxetine

Answer

Citalopram

Question 9

A patient with depression is being treated with chlorpromazine, but auditory hallucinations persist. Which of the following would be the most appropriate next medication to consider?

Accepted Answer

Clozapine

Answer

Haloperidol

Answer

Sulpiride

Answer

Tianeptine

Question 10

What is the normal therapeutic level of Lithium?

Accepted Answer

0.7 to 1.1 mEq/lit

Answer

0.5 to 0.7 mEq/lit

Answer

0.1 to 0.3 mEq/lit

Answer

1.5 to 2 mEq/lit

Psychopharmacology — MCQs

Psychopharmacology — MCQs

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