Psychopharmacology Practice Questions

Q: Which drug has proven efficacy in bipolar depression?

Lamotrigine. **Explanation:** The management of Bipolar Disorder is divided into two phases: treating acute episodes (mania or depression) and maintenance therapy. While many anticonvulsants act as mood stabilizers, their efficacy profiles differ significantly. **Why Lamotrigine is Correct:** **Lamotrigine** is unique among anticonvulsants because its primary strength lies in the **prevention and treatment of the depressive phase** of bipolar disorder. It acts by inhibiting voltage-gated sodium channels and modulating the release of glutamate. It is FDA-approved for the maintenance treatment of Bipolar I disorder to delay the time to occurrence of mood episodes, specifically depression. **Analysis of Incorrect Options:** * **Carbamazepine:** Primarily used for acute mania and prophylaxis. It is less effective for the depressive phase and is often considered a second-line agent due to its enzyme-inducing properties and side-effect profile. * **Valproate:** This is a first-line drug for **acute mania** and mixed episodes. While it is an excellent mood stabilizer for preventing future manic episodes, it has limited proven efficacy in treating acute bipolar depression. * **Tiagabine:** An anticonvulsant that works by inhibiting GABA reuptake (GAT-1 inhibitor). It has no established role or proven efficacy in the treatment of bipolar disorder. **High-Yield Clinical Pearls for NEET-PG:** * **The "Rash" Warning:** The most serious side effect of Lamotrigine is **Stevens-Johnson Syndrome (SJS)** or Toxic Epidermal Necrolysis. To minimize this risk, the drug must be started at a very low dose and titrated slowly ("Start low, go slow"). * **Drug Interaction:** Valproate inhibits the metabolism of Lamotrigine, significantly increasing its plasma levels and the risk of SJS. * **Other drugs for Bipolar Depression:** Apart from Lamotrigine, other first-line options include **Quetiapine**, **Lurasidone**, and the **Olanzapine-Fluoxetine combination (OFC)**.

Q: Which of the following drugs is used in Electroconvulsive Therapy (ECT)?

Atropine. **Explanation:** In Electroconvulsive Therapy (ECT), **Atropine** is the standard premedication used as an **anticholinergic (antimuscarinic) agent**. Its primary role is to prevent the profound vagal stimulation (parasympathetic surge) that occurs during the initial tonic phase of the seizure. This prevents complications such as severe bradycardia, arrhythmias, and transient asystole. Additionally, it helps reduce tracheobronchial and salivary secretions, minimizing the risk of aspiration. **Analysis of Options:** * **A. Atropine (Correct):** Used to block vagal bradycardia and dry secretions. Glycopyrrolate is a common alternative as it does not cross the blood-brain barrier. * **B. Labetalol:** While beta-blockers are sometimes used to manage the secondary hypertensive surge (sympathetic phase) in high-risk cardiac patients, they are not a standard premedication for all ECT patients and can interfere with seizure duration. * **C. Clonazepam:** This is a benzodiazepine with potent anticonvulsant properties. It is generally avoided or tapered before ECT because it raises the seizure threshold, potentially making the treatment ineffective. * **D. Cefixime:** This is a third-generation cephalosporin antibiotic and has no role in the psychiatric or anesthetic management of ECT. **High-Yield NEET-PG Pearls:** * **Standard ECT Premedication Sequence:** Anticholinergic (Atropine) → Induction Agent (Methohexital is gold standard; Propofol/Thiopental are alternatives) → Muscle Relaxant (Succinylcholine is the drug of choice). * **Absolute Contraindication:** Increased Intracranial Pressure (ICP) is the only absolute contraindication for ECT. * **Most Common Side Effect:** Retrograde amnesia and post-ictal confusion. * **Gold Standard for Depression:** ECT is the most effective treatment for severe, treatment-resistant depression and catatonia.

Q: A female suffering from psychosis, taking phenothiazines now complains of sudden onset of high grade fever, muscle rigidity, and altered sensorium. What is the diagnosis?

Neuroleptic malignant syndrome. ### Explanation The clinical presentation of **high-grade fever, muscle rigidity ("lead-pipe" type), and altered sensorium** in a patient taking antipsychotics (phenothiazines) is a classic description of **Neuroleptic Malignant Syndrome (NMS)**. #### Why the Correct Answer is Right NMS is a life-threatening idiosyncratic reaction to dopamine antagonists (typical antipsychotics like Haloperidol or Phenothiazines). The underlying pathophysiology involves **massive dopamine blockade** in the nigrostriatal pathway (causing rigidity) and the hypothalamus (causing thermoregulatory failure/fever). * **Key Tetrad:** Fever, Rigidity, Mental status changes, and Autonomic instability (tachycardia, labile BP). * **Lab findings:** Elevated Creatine Phosphokinase (CPK) due to muscle necrosis and leukocytosis. #### Why Other Options are Incorrect * **Malignant Hyperthermia:** While it presents with fever and rigidity, it is triggered by **volatile inhalation anesthetics** (e.g., Halothane) or succinylcholine, not antipsychotics. It involves a genetic defect in the ryanodine receptor. * **Tardive Dyskinesia:** A late-onset extrapyramidal side effect characterized by involuntary choreoathetoid movements (e.g., lip-smacking), but it does not cause fever or rigidity. * **Akathisia:** A subjective feeling of inner restlessness and the urge to move. It is the most common extrapyramidal side effect but lacks systemic symptoms like fever. #### NEET-PG High-Yield Pearls * **Drug of Choice:** **Dantrolene** (muscle relaxant) or **Bromocriptine** (dopamine agonist). * **Immediate Step:** Stop the offending antipsychotic and provide aggressive cooling/hydration. * **Mnemonic (FEVER):** **F**ever, **E**ncephalopathy, **V**itals unstable, **E**levated CPK, **R**igidity. * **Differentiation:** Unlike Serotonin Syndrome, NMS is characterized by "lead-pipe" rigidity rather than hyperreflexia/myoclonus.

Q: Lithium is best used in which of the following conditions?

Manic-depressive illness - Bipolar disorder. **Explanation:** **Lithium** is the "gold standard" mood stabilizer and the drug of choice for the prophylaxis and treatment of **Bipolar Disorder (Manic-Depressive Illness)**. 1. **Why Option A is Correct:** Lithium is most effective in classic Bipolar I disorder characterized by distinct episodes of mania and depression with relatively symptom-free intervals. It is highly effective in treating acute mania and is the only drug proven to significantly reduce the risk of suicide in these patients. It works by modulating second messenger systems (like the IP3 pathway) and inhibiting glycogen synthase kinase-3 (GSK-3). 2. **Why Other Options are Incorrect:** * **Option B (Unipolar Disorder):** While Lithium can be used as an *augmentation* strategy in treatment-resistant depression, it is not the first-line treatment for Unipolar Depression (where SSRIs are preferred). * **Option C (Rapid Cycling):** Rapid cycling is defined as ≥4 mood episodes in a year. Lithium is notoriously less effective in rapid cyclers and mixed episodes; **Sodium Valproate** or Carbamazepine are the preferred treatments here. * **Option D (Depression):** Lithium has limited efficacy as a monotherapy for acute depressive episodes compared to its anti-manic and prophylactic properties. **High-Yield Clinical Pearls for NEET-PG:** * **Therapeutic Index:** Narrow (0.6–1.2 mEq/L). Toxicity starts >1.5 mEq/L. * **Side Effects:** L-I-T-H: **L**eukocytosis, **I**nsipidus (Diabetes Insipidus), **T**remors/Teratogenicity (Ebstein’s Anomaly), **H**ypothyroidism. * **Monitoring:** Check Thyroid Function Tests (TFT) and Renal Function Tests (RFT) before starting. * **Drug Interactions:** Thiazides, NSAIDs, and ACE inhibitors increase Lithium levels (Risk of toxicity).

Q: What is the prophylactic plasma concentration range of lithium in mEq, and which of the following values does NOT fall within it?

0.5. Lithium is the gold standard for the treatment and prophylaxis of Bipolar Affective Disorder (BPAD). Because it has a **narrow therapeutic index** [2], monitoring serum lithium levels is critical to ensure efficacy and avoid toxicity. The therapeutic ranges for lithium are categorized based on the phase of treatment: 1. **Acute Mania:** 0.8 to 1.2 mEq/L (sometimes up to 1.5 mEq/L). 2. **Prophylaxis (Maintenance):** **0.6 to 1.2 mEq/L** [1]. **Why Option A is the correct answer:** The prophylactic range is strictly defined as **0.6–1.2 mEq/L** [1]. A value of **0.5 mEq/L** falls below this threshold. While it may provide some mood stabilization in sensitive patients, it is generally considered sub-therapeutic for effective long-term prophylaxis against manic or depressive relapses. **Analysis of Incorrect Options:** * **B (0.8 mEq/L):** This is the ideal "sweet spot" for maintenance therapy, balancing efficacy with a lower risk of side effects. * **C (0.6 mEq/L):** This is the lower limit of the prophylactic range. * **D (1.0 mEq/L):** This is well within the prophylactic range (0.6–1.2 mEq/L) and is often targeted for patients who do not respond to lower doses. **NEET-PG High-Yield Pearls:** * **Toxicity Levels:** Mild toxicity starts at >1.5 mEq/L; severe toxicity (seizures, coma) occurs at >2.0 mEq/L [2]. * **Monitoring:** Samples should be drawn **12 hours after the last dose** (trough levels). * **Drug Interactions:** Thiazides, NSAIDs, and ACE inhibitors increase lithium levels (by decreasing renal clearance), while Caffeine and Theophylline decrease lithium levels [1]. * **Side Effects:** Ebstein’s anomaly (teratogenic), Nephrogenic Diabetes Insipidus, and Hypothyroidism [1].

Q: Which antipsychotic medication is associated with fewer extrapyramidal side effects?

Quetiapine. ### Explanation **Correct Answer: C. Quetiapine** The risk of **Extrapyramidal Side Effects (EPS)** is primarily determined by a drug’s affinity for and occupancy of **Dopamine D2 receptors** in the nigrostriatal pathway. **Quetiapine** is a Second-Generation Antipsychotic (SGA) characterized by "loose" binding and rapid dissociation from D2 receptors. It also possesses potent **5-HT2A receptor antagonism**, which increases dopamine release in the striatum, further mitigating EPS. Among all antipsychotics, Quetiapine and Clozapine carry the lowest risk of EPS, making Quetiapine the drug of choice for treating psychosis in patients with **Parkinson’s Disease**. **Analysis of Incorrect Options:** * **A. Loxapine:** A typical (first-generation) antipsychotic of the dibenzoxazepine class. It has a high D2 affinity and a significant risk of EPS, especially at higher doses. * **B. Pimozide:** A high-potency typical antipsychotic used primarily for Tourette’s syndrome and Delusional Disorder (Monosymptomatic hypochondriacal psychosis). It has a very high risk of EPS and QT prolongation. * **C. Risperidone:** While an SGA, Risperidone is "atypical" only at low doses. At doses >6mg, its D2 occupancy increases significantly, making it the SGA with the **highest risk of EPS** and hyperprolactinemia. **High-Yield Clinical Pearls for NEET-PG:** * **Lowest EPS Risk:** Clozapine > Quetiapine. * **Highest EPS Risk (Typical):** Haloperidol, Fluphenazine. * **Highest EPS Risk (Atypical):** Risperidone. * **Metabolic Syndrome:** Quetiapine and Olanzapine carry high risks of weight gain and dyslipidemia (Clozapine is highest). * **Drug of Choice for Psychosis in Parkinson’s:** Quetiapine (Clozapine is also effective but requires blood monitoring).

Q: Which of the following drugs is used for lithium-induced tremors?

Propranolol. **Explanation:** **Lithium-induced tremors** are a common side effect of lithium therapy, typically presenting as a fine, symmetric, postural tremor of the hands. 1. **Why Propranolol is Correct:** The physiological mechanism behind lithium-induced tremors is thought to involve the stimulation of peripheral **beta-adrenergic receptors**. **Propranolol**, a non-selective beta-blocker, is the drug of choice because it effectively antagonizes these receptors, reducing the amplitude of the tremor. It is preferred over cardioselective beta-blockers because it crosses the blood-brain barrier and acts on both peripheral and central components of the tremor. 2. **Why Other Options are Incorrect:** * **Valproate:** While used as a mood stabilizer like lithium, it can actually *cause* or worsen tremors rather than treat them. * **Trihexyphenidyl:** This is an anticholinergic used for Parkinsonian (resting) tremors or extrapyramidal symptoms (EPS) caused by antipsychotics. Lithium tremors are postural, not Parkinsonian, and do not respond to anticholinergics. * **Tetrabenazine:** This is a VMAT2 inhibitor used for hyperkinetic movement disorders like Huntington’s chorea or Tardive Dyskinesia; it has no role in managing lithium toxicity or side effects. **High-Yield Clinical Pearls for NEET-PG:** * **Fine Tremors:** Occur at therapeutic lithium levels (0.6–1.2 mEq/L). * **Coarse Tremors:** A hallmark sign of **Lithium Toxicity** (>1.5 mEq/L); the first step in management is to check serum lithium levels. * **Management Tip:** Before starting Propranolol, always try reducing the lithium dose or switching to a sustained-release preparation. * **Contraindication:** Avoid Propranolol in patients with bronchial asthma or bradycardia.

Q: A 30-year-old patient with mania, prescribed haloperidol one week ago, has become restless and has been pacing for the last day. On examination, hand tremors are noted. What is the most likely diagnosis?

Akathisia. ### Explanation **Correct Answer: D. Akathisia** **Why it is correct:** Akathisia is a common **Extrapyramidal Side Effect (EPS)** associated with high-potency first-generation antipsychotics like Haloperidol. It is characterized by a subjective feeling of inner restlessness and an objective need to move. Clinically, this manifests as pacing, inability to sit still, or shifting weight from foot to foot. It typically occurs within days to weeks of starting or increasing the dose of an antipsychotic. The presence of hand tremors in this patient suggests concurrent drug-induced parkinsonism, which often co-exists with akathisia. **Why the other options are incorrect:** * **A. Anhedonia:** This refers to the inability to feel pleasure, a core symptom of depression or negative symptoms of schizophrenia, not a motor side effect. * **B. Dystonia:** Acute dystonia involves sudden, involuntary, sustained muscle contractions (e.g., torticollis, oculogyric crisis). It usually occurs within hours to the first few days of treatment, rather than presenting as continuous pacing. * **C. Restless Leg Syndrome (RLS):** While clinically similar, RLS typically occurs at night, is associated with uncomfortable sensations in the legs, and is relieved by movement. Akathisia is persistent throughout the day and is specifically linked to dopamine-blocking agents. **NEET-PG High-Yield Pearls:** * **Drug of Choice (DOC):** For Akathisia, the first-line treatment is **Propranolol** (Beta-blocker). Centrally acting anticholinergics (like Benztropine) are less effective for akathisia than for dystonia. * **Timeline of EPS:** 1. **Acute Dystonia:** Hours to days. 2. **Akathisia:** Days to weeks. 3. **Parkinsonism:** Weeks to months. 4. **Tardive Dyskinesia:** Months to years (long-term use). * **Mechanism:** Akathisia is thought to result from dopamine (D2) blockade in the nigrostriatal pathway.

Q: Which of the following drug classes is most useful for acute depression and has a good side effect profile?

Selective Serotonin Reuptake Inhibitors (SSRIs). **Explanation:** **Selective Serotonin Reuptake Inhibitors (SSRIs)** are considered the first-line treatment for acute depression. Their primary mechanism involves inhibiting the presynaptic reuptake of serotonin (5-HT), thereby increasing its availability in the synaptic cleft. They are preferred because they possess a **high therapeutic index**, lack significant anticholinergic or cardiotoxic effects, and are safe in overdose, making them the gold standard for both efficacy and tolerability. **Analysis of Incorrect Options:** * **Tricyclic Antidepressants (TCAs):** While highly effective, they have a narrow therapeutic index. They cause significant side effects (sedation, weight gain, dry mouth) and are **lethal in overdose** due to cardiotoxicity (arrhythmias via sodium channel blockade). * **Non-selective MAO-Is:** These are rarely used first-line due to the risk of **Hypertensive Crisis** ("Cheese Reaction") when taken with tyramine-rich foods and the risk of Serotonin Syndrome. * **RIMA (e.g., Moclobemide):** Although safer than non-selective MAO-Is, they are generally considered second-line or adjunctive and do not have the extensive clinical evidence base or "all-rounder" profile of SSRIs for acute depression. **High-Yield Clinical Pearls for NEET-PG:** * **Most common side effect of SSRIs:** Gastrointestinal upset (nausea/diarrhea) and sexual dysfunction. * **Drug of choice (DOC)** for Depression in patients with recent Myocardial Infarction: **Sertraline**. * **Fluoxetine** has the longest half-life, reducing the risk of discontinuation syndrome. * **Fluvoxamine** is specifically preferred for Obsessive-Compulsive Disorder (OCD).

Question 1

Which drug has proven efficacy in bipolar depression?

Accepted Answer

Lamotrigine

Answer

Carbamazepine

Answer

Valproate

Answer

Tiagabine

Question 2

Which of the following drugs is used in Electroconvulsive Therapy (ECT)?

Accepted Answer

Atropine

Answer

Labetalol

Answer

Clonazepam

Answer

Cefixime

Question 3

A female suffering from psychosis, taking phenothiazines now complains of sudden onset of high grade fever, muscle rigidity, and altered sensorium. What is the diagnosis?

Accepted Answer

Neuroleptic malignant syndrome

Answer

Malignant hyperthermia

Answer

Tardive dyskinesia

Answer

Akathesia

Question 4

Lithium is best used in which of the following conditions?

Accepted Answer

Manic-depressive illness - Bipolar disorder

Answer

Manic-depressive illness - Unipolar disorder

Answer

Manic-depressive illness - Rapid cycling

Answer

Depression

Question 5

What is the prophylactic plasma concentration range of lithium in mEq, and which of the following values does NOT fall within it?

Accepted Answer

0.5

Answer

0.8

Answer

0.6

Answer

1.0

Question 6

Which antipsychotic medication is associated with fewer extrapyramidal side effects?

Accepted Answer

Quetiapine

Answer

Loxapine

Answer

Pimozide

Answer

Risperidone

Question 7

What is the drug of choice for psychosis in Parkinson's disease?

Accepted Answer

Clozapine

Answer

Haloperidol

Answer

Lithium

Answer

Risperidone

Question 8

Which of the following drugs is used for lithium-induced tremors?

Accepted Answer

Propranolol

Answer

Valproate

Answer

Trihexyphenidyl

Answer

Tetrabenazine

Question 9

A 30-year-old patient with mania, prescribed haloperidol one week ago, has become restless and has been pacing for the last day. On examination, hand tremors are noted. What is the most likely diagnosis?

Accepted Answer

Akathisia

Answer

Anhedonia

Answer

Dystonia

Answer

Restless leg syndrome

Question 10

Which of the following drug classes is most useful for acute depression and has a good side effect profile?

Accepted Answer

Selective Serotonin Reuptake Inhibitors (SSRIs)

Answer

Reversible Inhibitors of Monoamine Oxidase A (RIMA)

Answer

Tricyclic Antidepressants

Answer

Non-selective Monoamine Oxidase Inhibitors (MAO-inhibitors)

Psychopharmacology — MCQs

Psychopharmacology — MCQs

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