Psychopharmacology — MCQs
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A 25-year-old man presents to the emergency ward with complaints of 'stiffness and twisting' of his neck and jaw. He describes these symptoms as very uncomfortable and completely involuntary. His medications include lithium and trifluoperazine. Which of the following is the next immediate step in management?
Which of the following is a known adverse effect of lithium?
Which of the following is NOT a side effect of lithium used in psychiatric practice?
Which of the following drugs can cause hyperprolactinemia?
What is true regarding akathisia?
Which of the following conditions makes antipsychotics relatively safer to use?
Which serum lithium level is suggestive of toxicity?
Which of the following is an extrapyramidal side effect of antipsychotics?
What is the drug of choice for panic disorders?
Which mood stabilizer has anti-suicidal properties?
Psychopharmacology Indian Medical PG Practice Questions and MCQs
Question 151: A 25-year-old man presents to the emergency ward with complaints of 'stiffness and twisting' of his neck and jaw. He describes these symptoms as very uncomfortable and completely involuntary. His medications include lithium and trifluoperazine. Which of the following is the next immediate step in management?
- A. Intravenous lorazepam
- B. Intramuscular benztropine (Correct Answer)
- C. Diphenhydramine
- D. Trifluoperazine
Explanation: **Explanation:** The patient is presenting with **Acute Dystonia**, a common Extrapyramidal Side Effect (EPS) associated with typical antipsychotics like **Trifluoperazine**. It typically occurs within hours to days of starting the medication or increasing the dose. The "stiffness and twisting" of the neck (torticollis) and jaw (oromandibular dystonia) are hallmark signs caused by a sudden blockade of dopamine (D2) receptors in the nigrostriatal pathway, leading to a relative excess of cholinergic activity. **Why Intramuscular Benztropine is correct:** The immediate management of acute dystonia requires restoring the dopamine-acetylcholine balance. **Anticholinergic agents** are the treatment of choice. **Benztropine** (or Promethazine) administered via the **intramuscular (IM)** or intravenous (IV) route provides rapid relief, usually within 15–20 minutes. **Analysis of Incorrect Options:** * **A. Intravenous Lorazepam:** While benzodiazepines can help with muscle relaxation and anxiety, they are not the primary treatment for dystonia and are less effective than anticholinergics. * **C. Diphenhydramine:** While diphenhydramine (an antihistamine with anticholinergic properties) is an effective treatment, **Benztropine** is generally considered the first-line gold standard in clinical guidelines and exam scenarios for its potent anticholinergic profile. * **D. Trifluoperazine:** This is the offending agent. Continuing or increasing the dose would worsen the dystonia. **NEET-PG High-Yield Pearls:** * **Risk Factors:** Young males and those on high-potency typical antipsychotics (Haloperidol, Fluphenazine, Trifluoperazine) are at highest risk. * **Common Presentations:** Torticollis (neck), Retrocollis (head back), Oculogyric crisis (eyes rolling up), and Trismus (clenched jaw). * **Sequence of EPS:** Remember the rule of **4s**: **4 hours** (Acute Dystonia), **4 days/weeks** (Akathisia), **4 weeks/months** (Parkinsonism), **4 years** (Tardive Dyskinesia). * **Prophylaxis:** If the antipsychotic must be continued, oral anticholinergics are often co-prescribed for several weeks to prevent recurrence.
Question 152: Which of the following is a known adverse effect of lithium?
- A. Agranulocytosis
- B. Altered judgement
- C. Aplastic anemia
- D. Hypothyroidism (Correct Answer)
Explanation: **Explanation:** **Lithium** is the gold-standard mood stabilizer for Bipolar Disorder, but it has a narrow therapeutic index and affects multiple organ systems, most notably the thyroid and kidneys. **1. Why Hypothyroidism is Correct:** Lithium interferes with thyroid hormone synthesis and release through several mechanisms: it inhibits iodine uptake into follicular cells, interferes with iodotyrosine coupling, and inhibits the release of T4 and T3. This leads to a compensatory rise in Thyroid Stimulating Hormone (TSH). Approximately 5–15% of patients on long-term lithium therapy develop **hypothyroidism** (more common in females). It is typically managed with Levothyroxine supplementation rather than discontinuing lithium. **2. Why the Other Options are Incorrect:** * **Agranulocytosis:** This is a life-threatening side effect classically associated with **Clozapine** (an atypical antipsychotic), requiring mandatory WBC monitoring. Lithium, conversely, often causes *leukocytosis* (benign increase in WBC count). * **Altered Judgement:** While lithium toxicity can cause confusion or delirium, "altered judgement" is not a recognized side effect of therapeutic lithium. In fact, lithium stabilizes mood and improves cognitive clarity in manic patients. * **Aplastic Anemia:** This is a rare but serious side effect associated with **Carbamazepine** (another mood stabilizer) or Felbamate, but not lithium. **High-Yield Clinical Pearls for NEET-PG:** * **Renal Side Effect:** Nephrogenic Diabetes Insipidus (treated with Amiloride). * **Teratogenicity:** Ebstein’s Anomaly (tricuspid valve displacement). * **Therapeutic Range:** 0.6–1.2 mEq/L (Prophylaxis: 0.6–0.8; Acute Mania: 0.8–1.2). * **ECG Changes:** T-wave flattening or inversion (similar to hypokalemia). * **Monitoring:** Check TSH and Serum Creatinine before starting and every 6–12 months.
Question 153: Which of the following is NOT a side effect of lithium used in psychiatric practice?
- A. Nausea, vomiting
- B. Tremors
- C. Hypothyroidism
- D. Hypercalcemia (Correct Answer)
Explanation: **Explanation:** Lithium is the gold-standard mood stabilizer for Bipolar Affective Disorder (BPAD). However, it has a narrow therapeutic index (0.6–1.2 mEq/L), leading to a wide range of side effects across multiple organ systems. **Why Hypercalcemia is the Correct Answer:** Actually, the question asks for what is **NOT** a side effect, but there is a clinical nuance here. Lithium **does** cause hypercalcemia and hyperparathyroidism by increasing the set-point of the calcium-sensing receptor in the parathyroid gland. In many standard PG entrance exams, if "Hypercalcemia" is marked as the "not a side effect" option, it is often a technical error in the question bank or refers to the fact that lithium typically causes **Hypercalcemia**, not Hypocalcemia. *Note: If the option were Hypocalcemia, it would be the definitive "not a side effect."* **Analysis of Other Options:** * **Nausea/Vomiting (Option A):** These are the most common **early** gastrointestinal side effects. They are usually dose-dependent and can be managed by taking the drug after meals. * **Tremors (Option B):** Fine tremors of the hands are a very common side effect. Conversely, **coarse tremors** are a hallmark sign of Lithium Toxicity. * **Hypothyroidism (Option C):** Lithium inhibits the release of thyroid hormones (T3/T4) and interferes with iodine organification. It is a classic cause of drug-induced goiter and hypothyroidism. **High-Yield Clinical Pearls for NEET-PG:** * **L-I-T-H:** **L**eukocytosis (Benign), **I**nsipidus (Nephrogenic Diabetes Insipidus), **T**remors/Teratogenicity (Ebstein’s Anomaly), **H**ypothyroidism/Hypercalcemia. * **Monitoring:** Thyroid Function Tests (TFT) and Renal Function Tests (RFT) must be done before starting and every 6–12 months. * **Toxicity:** Precipitated by NSAIDs, Thiazides, and ACE inhibitors (which decrease lithium clearance). * **Drug of Choice:** For acute mania and prophylaxis of BPAD.
Question 154: Which of the following drugs can cause hyperprolactinemia?
- A. Olanzapine
- B. Ziprasidone
- C. Risperidone (Correct Answer)
- D. Asenapine
Explanation: **Explanation:** The correct answer is **Risperidone**. **Mechanism of Action:** Hyperprolactinemia in patients taking antipsychotics is caused by the blockade of **D2 receptors** in the **tuberoinfundibular pathway** of the brain. Under normal physiological conditions, dopamine acts as a "prolactin-inhibiting factor." When D2 receptors are blocked, the inhibition is removed, leading to increased prolactin secretion from the anterior pituitary. **Why Risperidone?** While Risperidone is classified as an atypical (second-generation) antipsychotic, it is unique because it has a very high affinity for D2 receptors and poor penetration of the blood-brain barrier in the pituitary region. Consequently, it behaves more like a typical antipsychotic regarding prolactin elevation. It is the **most common atypical antipsychotic** associated with significant hyperprolactinemia, often causing galactorrhea, amenorrhea, and gynecomastia. **Analysis of Incorrect Options:** * **Olanzapine:** While it can cause mild, transient elevations in prolactin, it is generally considered "prolactin-sparing" compared to Risperidone. * **Ziprasidone & Asenapine:** These are second-generation antipsychotics with low potential for prolactin elevation. They dissociate quickly from D2 receptors, minimizing the impact on the tuberoinfundibular pathway. **High-Yield Clinical Pearls for NEET-PG:** * **Highest Risk:** Typical antipsychotics (e.g., Haloperidol) and Risperidone/Paliperidone. * **Lowest Risk (Prolactin-sparing):** Aripiprazole (a D2 partial agonist), Quetiapine, and Clozapine. * **Management:** If hyperprolactinemia occurs, the drug of choice to add (if switching is not possible) is **Aripiprazole**, as its partial agonism helps lower prolactin levels. * **Clinical Features:** Look for "Amenorrhea-Galactorrhea syndrome" in females and "Gynecomastia/Sexual dysfunction" in males.
Question 155: What is true regarding akathisia?
- A. Treatment is by anticholinergics. (Correct Answer)
- B. The patient wanders away from home.
- C. It presents with hallucinations.
- D. Behavioral therapy is required.
Explanation: **Explanation:** **Akathisia** is the most common extrapyramidal side effect (EPS) associated with antipsychotic medications (especially first-generation antipsychotics). It is characterized by a subjective feeling of inner restlessness and an objective need to be in constant motion. **Why Option A is Correct:** The primary management for akathisia involves reducing the dose of the offending antipsychotic or switching to a drug with lower EPS potential. Pharmacologically, **centrally acting anticholinergics** (e.g., Procyclidine, Benztropine) and **Beta-blockers** (Proanolol is considered the drug of choice) are the mainstays of treatment. Anticholinergics help restore the dopamine-acetylcholine balance in the nigrostriatal pathway. **Why Other Options are Incorrect:** * **Option B:** Wandering away from home is characteristic of a **Dissociative Fugue** or certain dementias, not akathisia. In akathisia, the patient moves restlessly (pacing, tapping feet) but remains aware of their surroundings. * **Option C:** Akathisia is a motor/sensory side effect; it does not involve **hallucinations**, which are psychotic symptoms. * **Option D:** Akathisia is a drug-induced physiological reaction. **Behavioral therapy** is ineffective; medical intervention or dosage adjustment is mandatory. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC):** Proanolol (Beta-blocker) is often cited as the most effective treatment for akathisia. * **Clinical Presentation:** Patients often describe "jumping out of their skin" or an inability to sit still. * **Differential Diagnosis:** Must be distinguished from psychotic agitation; increasing the antipsychotic dose will worsen akathisia but improve agitation. * **Timeline:** Usually occurs within days to weeks of starting or increasing antipsychotic medication.
Question 156: Which of the following conditions makes antipsychotics relatively safer to use?
- A. Infertility
- B. Hypertension (Correct Answer)
- C. Epilepsy
- D. All of the above
Explanation: **Explanation:** The correct answer is **Hypertension**. This question tests your understanding of the side-effect profile of antipsychotics and their contraindications. **1. Why Hypertension is the correct answer:** Most antipsychotics (especially low-potency typicals like Chlorpromazine and certain atypicals like Clozapine) cause **orthostatic hypotension** due to **alpha-1 adrenergic blockade**. In patients with hypertension, this side effect may actually lead to a reduction in blood pressure. While blood pressure must still be monitored to avoid profound hypotension, the presence of hypertension does not pose an inherent risk of exacerbation by the drug, unlike the other conditions listed. **2. Why the other options are incorrect:** * **Infertility:** Antipsychotics (especially Risperidone and typicals) are potent **D2 receptor antagonists** in the tuberoinfundibular pathway. This leads to **hyperprolactinemia**, which suppresses the HPO axis, causing amenorrhea and galactorrhea in women and decreased spermatogenesis in men. Thus, they can worsen or cause infertility. * **Epilepsy:** Antipsychotics **lower the seizure threshold**. This is a significant concern in patients with pre-existing epilepsy. Clozapine and Chlorpromazine carry the highest risk of inducing seizures. **High-Yield Clinical Pearls for NEET-PG:** * **Clozapine:** Highest risk of seizures (dose-dependent) and agranulocytosis. * **Thioridazine:** Known for QTc prolongation and retinitis pigmentosa. * **Hyperprolactinemia:** Least common with Aripiprazole (D2 partial agonist) and Quetiapine. * **Metabolic Syndrome:** Most common with Clozapine and Olanzapine; least common with Ziprasidone and Aripiprazole.
Question 157: Which serum lithium level is suggestive of toxicity?
- A. 2 mEq/L (Correct Answer)
- B. 4 mEq/L
- C. 6 mEq/L
- D. 8 mEq/L
Explanation: Lithium is a mood stabilizer with a **narrow therapeutic index**, meaning the margin between a therapeutic dose and a toxic dose is very small. Regular monitoring of serum lithium levels is mandatory for patient safety. ### **Explanation of the Correct Answer** The therapeutic range for lithium is generally **0.6 to 1.2 mEq/L**. Toxicity typically manifests when serum levels exceed **1.5 mEq/L**. * **Mild to Moderate Toxicity (1.5–2.0 mEq/L):** Presents with vomiting, abdominal pain, ataxia, dizziness, and coarse tremors. * **Severe Toxicity (>2.0 mEq/L):** Can lead to seizures, coma, cardiac arrhythmias, and permanent neurological damage. Among the given options, **2 mEq/L** is the earliest threshold indicating significant toxicity requiring immediate clinical intervention. ### **Explanation of Incorrect Options** * **4, 6, and 8 mEq/L:** While these levels are indeed toxic, they represent extreme, life-threatening emergencies. In clinical practice and exams, toxicity is defined by the *lowest* level that crosses the therapeutic threshold. Levels above 3.5–4.0 mEq/L are often fatal and usually necessitate emergency hemodialysis. ### **High-Yield NEET-PG Pearls** * **Monitoring:** Serum levels should be checked **12 hours after the last dose** (Trough level). * **Steady State:** It takes about **5 days** to reach a steady state after starting or changing a dose. * **Side Effects:** Fine tremors (therapeutic), Coarse tremors (toxic), Nephrogenic Diabetes Insipidus, and Ebstein’s Anomaly (teratogenic). * **Drug Interactions:** **NSAIDs, Thiazides, and ACE inhibitors** increase lithium levels by decreasing renal clearance (Mnemonic: **"NAT"**). * **Management of Toxicity:** Hydration is first-line; **Hemodialysis** is the treatment of choice for severe toxicity (>2.5–4.0 mEq/L or if the patient is symptomatic).
Question 158: Which of the following is an extrapyramidal side effect of antipsychotics?
- A. Dystonia (Correct Answer)
- B. Akathisia
- C. Seizures
- D. Diarrhoea
Explanation: **Explanation:** **Extrapyramidal Side Effects (EPS)** are drug-induced movement disorders caused by the blockade of dopamine (D2) receptors in the **nigrostriatal pathway** [1]. This is most commonly associated with First-Generation Antipsychotics (e.g., Haloperidol). **1. Why Dystonia is Correct:** **Acute Dystonia** is a classic EPS characterized by sudden, involuntary muscle spasms. Common presentations include torticollis (neck twisting), grimacing, and **oculogyric crisis** (upward deviation of eyes). It typically occurs within hours to days of starting treatment or increasing the dose. **2. Analysis of Incorrect Options:** * **Akathisia (Option B):** While Akathisia (subjective restlessness) is indeed an EPS [1], in the context of single-choice questions where "Dystonia" is the primary textbook example of an acute motor spasm, it serves as a distractor if Dystonia is the intended focus. *Note: In many clinical exams, both are EPS; however, Dystonia is the most "definitive" motor spasm.* * **Seizures (Option C):** This is a neurological side effect (lowering of seizure threshold), particularly with **Clozapine** [2], but it is not classified as an extrapyramidal motor symptom. * **Diarrhoea (Option D):** Antipsychotics typically have **anticholinergic** properties, which cause constipation, not diarrhoea. **High-Yield Clinical Pearls for NEET-PG:** * **Timeline of EPS:** 1. **Acute Dystonia:** Hours to days (Treatment: Promethazine or Benztropine) [1]. 2. **Akathisia:** Days to weeks (Treatment: Beta-blockers like Propranolol) [1]. 3. **Drug-induced Parkinsonism:** Weeks to months (Treatment: Trihexyphenidyl) [1]. 4. **Tardive Dyskinesia:** Months to years (Choreoathetoid movements; Treatment: Valbenazine) [1]. * **Pathophysiology:** EPS occurs when D2 blockade in the striatum leads to a relative **excess of Acetylcholine**. This is why anticholinergics are used for management [1].
Question 159: What is the drug of choice for panic disorders?
- A. Nitrazepam
- B. Imipramine (Correct Answer)
- C. Diazepam
- D. Clonidine
Explanation: **Explanation:** **1. Why Imipramine is the correct answer:** Imipramine is a **Tricyclic Antidepressant (TCA)** and was historically the first drug proven effective for the treatment of panic disorder. It works by inhibiting the reuptake of norepinephrine and serotonin. While **Selective Serotonin Reuptake Inhibitors (SSRIs)** are currently considered the first-line treatment in modern clinical practice due to a better side-effect profile, **Imipramine remains the classic "Drug of Choice" (DOC) in many standard textbooks and traditional NEET-PG patterns** because of its established efficacy in preventing panic attacks. **2. Why the other options are incorrect:** * **Nitrazepam:** This is a long-acting benzodiazepine primarily used for insomnia. It is not indicated for the long-term management of panic disorder. * **Diazepam:** While a benzodiazepine (like Alprazolam) can provide rapid relief for acute anxiety, it is generally avoided as a long-term DOC due to the risks of sedation, cognitive impairment, and dependence. It does not treat the underlying pathophysiology as effectively as antidepressants. * **Clonidine:** An alpha-2 agonist used primarily for hypertension and opioid withdrawal. While it can reduce some autonomic symptoms of anxiety, it is not a primary treatment for panic disorder. **3. High-Yield Clinical Pearls for NEET-PG:** * **Current First-line:** SSRIs (e.g., Sertraline, Paroxetine) are the modern first-line agents. * **Acute Attack:** For immediate relief of a panic attack, short-acting benzodiazepines like **Alprazolam** are used. * **Treatment Duration:** Pharmacotherapy for panic disorder should typically continue for 8–12 months to prevent relapse. * **Cognitive Behavioral Therapy (CBT):** This is the most effective non-pharmacological treatment and is often combined with medication.
Question 160: Which mood stabilizer has anti-suicidal properties?
- A. Lithium (Correct Answer)
- B. Carbamazepine
- C. Lamotrigine
- D. Valproate
Explanation: **Explanation:** **Lithium** is the gold-standard mood stabilizer and is uniquely recognized for its potent **anti-suicidal properties**. Unlike other mood stabilizers, its ability to reduce the risk of completed suicide and suicide attempts in patients with Bipolar Disorder and Major Depressive Disorder is independent of its mood-stabilizing effect. The exact mechanism is not fully understood but is thought to involve the reduction of impulsivity and aggression by modulating serotonergic neurotransmission. **Analysis of Incorrect Options:** * **Carbamazepine (B):** While effective for acute mania and prophylaxis, it has no proven specific anti-suicidal efficacy. * **Lamotrigine (C):** Excellent for preventing bipolar depression, but it does not possess the specific anti-suicidal profile associated with Lithium. * **Valproate (D):** A first-line agent for mania (especially rapid cycling), but studies have not consistently demonstrated a reduction in suicide rates comparable to Lithium. **High-Yield Clinical Pearls for NEET-PG:** * **The "Anti-Suicide" Duo:** Only two psychiatric medications are classically recognized for reducing suicide risk: **Lithium** (in Bipolar/Mood disorders) and **Clozapine** (in Schizophrenia). * **Therapeutic Index:** Lithium has a narrow therapeutic index. Target serum levels are **0.8–1.2 mEq/L** for acute mania and **0.6–1.0 mEq/L** for maintenance. * **Monitoring:** Before starting Lithium, always check **Thyroid Function Tests (TFT)** and **Renal Function Tests (RFT)**, as it can cause hypothyroidism and nephrogenic diabetes insipidus. * **Teratogenicity:** Lithium use in pregnancy is associated with **Ebstein’s Anomaly** (tricuspid valve displacement).
Practice by Chapter
Principles of Psychopharmacology
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Antipsychotic Medications
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Antidepressant Medications
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Mood Stabilizers
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Anxiolytics and Hypnotics
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Stimulants and Cognitive Enhancers
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Pharmacokinetics and Pharmacodynamics
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Drug Interactions
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Adverse Effects and Management
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Pharmacogenomics in Psychiatry
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Special Populations Considerations
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Treatment Algorithms and Guidelines
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