Substance Use Disorders — MCQs

A 35-year-old female presents for smoking cessation. She was diagnosed with depression two years ago and took SSRIs for six months, but has been off medication for 1.5 years and is currently mentally healthy. She started smoking at age 25 and has attempted to quit multiple times using nicotine gum, but has been unable to sustain abstinence for more than one month. What is the best recommendation for this patient?

Q307Easy

Hallucinations are primarily produced by which of the following substances?

Q308Easy

Which of the following is a symptom of opioid withdrawal?

Q309Medium

A 40-year-old chronic alcoholic presents to the emergency room with acute onset of visual hallucinations (seeing snakes), failure to recognize family members, violent behavior, and tremulousness for a few hours. The patient has abstained from alcohol for 2 days. Examination reveals elevated blood pressure, tremors, increased psychomotor activity, fearful affect, hallucinatory behavior, disorientation, and impaired judgment and insight. What is the most likely diagnosis?

Q310Medium

Which of the following is false regarding delirium tremens?

Substance Use Disorders Indian Medical PG Practice Questions and MCQs

Question 301: What is the first symptom to appear in alcohol withdrawal?

A. Visual hallucinations
B. Sleep disturbance
C. Tremors (Correct Answer)
D. Delirium

Explanation: **Explanation:** Alcohol withdrawal occurs due to the sudden cessation of alcohol intake, which leads to **CNS hyperexcitability**. Chronic alcohol use enhances GABA (inhibitory) activity and inhibits NMDA (excitatory) receptors. When alcohol is removed, the brain is left in a state of GABA deficiency and glutamate excess. **1. Why Tremors are correct:** **Tremors** (specifically "coarse tremors" of the hands) are the **earliest and most common** objective sign of alcohol withdrawal. They typically appear within **6 to 12 hours** after the last drink. This stage is often referred to as "the shakes." **2. Analysis of Incorrect Options:** * **Visual Hallucinations:** These typically occur **12 to 24 hours** after cessation (Alcoholic Hallucinosis). Unlike delirium tremens, the patient usually has a clear sensorium (is oriented). * **Sleep Disturbance:** While insomnia and irritability occur early, they are subjective symptoms. In the hierarchy of clinical signs for exams, tremors are the definitive "first symptom/sign" recognized in the withdrawal timeline. * **Delirium (Delirium Tremens):** This is the most severe form of withdrawal, occurring **48 to 96 hours** after the last drink. It is characterized by clouding of consciousness, autonomic instability, and global confusion. **3. High-Yield Clinical Pearls for NEET-PG:** * **Timeline Summary:** Tremors (6-12h) → Hallucinations (12-24h) → Seizures (6-48h; "Rum fits") → Delirium Tremens (48-96h). * **Rum Fits:** These are typically Generalized Tonic-Clonic Seizures (GTCS) occurring within 48 hours. * **Treatment of Choice:** Benzodiazepines (e.g., Diazepam, Lorazepam) are the gold standard to prevent progression to delirium. * **Wernicke’s Encephalopathy:** Always give **Thiamine before Glucose** to prevent precipitating this condition.

Question 302: What is the drug of choice in delirium tremens?

A. Chlorpromazine
B. Phenytoin
C. Chlordiazepoxide (Correct Answer)
D. Morphine

Explanation: **Explanation:** **Delirium Tremens (DT)** is the most severe form of alcohol withdrawal, characterized by altered sensorium, autonomic hyperactivity, and hallucinations. The underlying pathophysiology involves a state of **GABA deficiency** and **NMDA (Glutamate) hyperactivity** due to chronic alcohol consumption. **Why Chlordiazepoxide is the Correct Choice:** Benzodiazepines (BZDs) are the gold standard for managing alcohol withdrawal. They act as cross-tolerant agents that enhance GABAergic neurotransmission, effectively "substituting" for the missing alcohol. **Chlordiazepoxide** is a long-acting BZD with active metabolites, providing a "self-tapering" effect that ensures a smooth recovery and prevents breakthrough seizures or recurrence of delirium. In clinical practice, while Lorazepam is preferred in patients with liver failure (due to extrahepatic metabolism), Chlordiazepoxide remains the classic textbook drug of choice for stable patients. **Analysis of Incorrect Options:** * **Chlorpromazine (Antipsychotic):** It lowers the seizure threshold. Since alcohol withdrawal already predisposes a patient to seizures (rum fits), antipsychotics are contraindicated as monotherapy. * **Phenytoin (Antiepileptic):** It is ineffective for alcohol withdrawal seizures, which are caused by GABA-withdrawal rather than a primary focal seizure focus. * **Morphine (Opioid):** It has no role in alcohol withdrawal and can cause respiratory depression or mask signs of autonomic instability. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of choice for Alcohol Withdrawal Seizures:** Intravenous Diazepam. * **BZD of choice in Liver Disease (CLD):** Lorazepam, Oxazepam, or Temazepam (Mnemonic: **LOT**—they do not undergo oxidative metabolism in the liver). * **Wernicke’s Encephalopathy:** Always administer Thiamine *before* Glucose to prevent precipitating acute neurological deterioration.

Question 303: Naltrexone is used for which of the following conditions?

A. Cocaine dependence
B. Alcohol dependence (Correct Answer)
C. Anorexia nervosa
D. Cannabis toxicity

Explanation: **Explanation:** **Naltrexone** is a long-acting **mu-opioid receptor antagonist**. Its primary use in **Alcohol Dependence** (Option B) is based on its ability to block the endogenous opioid system. When alcohol is consumed, it triggers the release of dopamine in the reward pathway (nucleus accumbens) via opioid receptors. By blocking these receptors, Naltrexone reduces the "high" or pleasurable effects of alcohol, thereby **decreasing cravings** and reducing the likelihood of relapse. It is FDA-approved for both alcohol and opioid use disorders. **Why other options are incorrect:** * **Cocaine dependence (A):** There is no FDA-approved pharmacological treatment for cocaine dependence. Management is primarily psychosocial (e.g., Contingency Management). * **Anorexia nervosa (C):** Treatment focuses on nutritional rehabilitation and psychotherapy (CBT). While SSRIs may be used for comorbid depression/OCD, Naltrexone has no established role. * **Cannabis toxicity (D):** Management is supportive (e.g., benzodiazepines for agitation). There is no specific antagonist for cannabinoids. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Competitive antagonist at $\mu$ and $\kappa$ opioid receptors. * **Prerequisite:** Patients must be **opioid-free for 7–10 days** before starting Naltrexone to avoid precipitating acute withdrawal. * **Contraindication:** Acute hepatitis or liver failure (it is hepatotoxic at high doses). * **Acamprosate vs. Naltrexone:** While Naltrexone reduces cravings/heavy drinking, Acamprosate is preferred for maintaining abstinence in patients with liver disease (as it is renally excreted). * **Disulfiram:** Works via **aversive conditioning** by inhibiting aldehyde dehydrogenase, causing a toxic buildup of acetaldehyde.

Question 304: Which of the following is an anticraving drug used in alcohol dependence?

A. Buprenorphine
B. Acamprosate (Correct Answer)
C. Disulfiram
D. Diazepam

Explanation: **Explanation:** **Acamprosate (Option B)** is the correct answer. It is a structural analogue of GABA and acts as a glutamate receptor modulator (specifically an NMDA receptor antagonist). In chronic alcohol use, the brain compensates for alcohol’s inhibitory effects by upregulating excitatory glutamate receptors. During abstinence, this results in a "hyper-glutamatergic" state, leading to cravings and withdrawal. Acamprosate restores this chemical balance, thereby reducing the urge to drink (anticraving effect). It is primarily excreted by the kidneys and is the drug of choice for patients with liver disease. **Analysis of Incorrect Options:** * **Buprenorphine (Option A):** A partial mu-opioid agonist used in the management of **Opioid Use Disorder**, not alcohol dependence. * **Disulfiram (Option C):** This is an **Aversive Agent**, not an anticraving drug. It inhibits aldehyde dehydrogenase, causing a buildup of acetaldehyde if alcohol is consumed, leading to unpleasant symptoms (nausea, flushing, tachycardia). It deters drinking through fear of reaction rather than reducing the desire to drink. * **Diazepam (Option D):** A benzodiazepine used for the management of **Acute Alcohol Withdrawal** to prevent seizures and delirium tremens. It has no role in long-term maintenance or craving reduction. **High-Yield NEET-PG Pearls:** * **Naltrexone:** Another first-line anticraving drug (opioid antagonist). It reduces the "reward/pleasure" of drinking. * **Drug of Choice for Liver Cirrhosis:** Acamprosate (since Naltrexone and Disulfiram are hepatotoxic). * **Drug of Choice for Renal Failure:** Naltrexone (since Acamprosate is renally cleared). * **Topiramate & Baclofen:** Second-line agents also used to reduce alcohol cravings.

Question 305: A patient with alcohol dependence was prescribed a medication, and advised to avoid alcohol due to potential adverse drug interactions. Which of the following medications is known for this interaction?

A. Disulfiram (Correct Answer)
B. Acamprosate
C. Naloxone
D. Naltrexone

Explanation: **Explanation:** **1. Why Disulfiram is correct:** Disulfiram is an **aldehyde dehydrogenase (ALDH) inhibitor** [1]. It is used as an aversion therapy agent in alcohol dependence. When a patient consumes alcohol while on Disulfiram, the metabolism of ethanol is arrested at the **Acetaldehyde** stage [1]. The resulting accumulation of acetaldehyde leads to the **Disulfiram-Ethanol Reaction (DER)** [3]. This is characterized by intense flushing, tachycardia, palpitations, nausea, vomiting, and hypotension [1]. Patients are strictly advised to avoid alcohol (including hidden sources like aftershaves or cough syrups) [1], [3] to prevent this distressing and potentially fatal reaction [2]. **2. Why the other options are incorrect:** * **Acamprosate:** An NMDA receptor antagonist and GABA-A enhancer used to maintain abstinence [1]. It does not cause a physical reaction if alcohol is consumed; its primary side effect is diarrhea. * **Naltrexone:** An opioid antagonist that reduces the "craving" and "reward" (euphoria) associated with drinking by blocking mu-opioid receptors [1]. It does not cause a disulfiram-like reaction. * **Naloxone:** A short-acting opioid antagonist used primarily for the emergency reversal of **opioid overdose**, not for the long-term management of alcohol dependence. **3. NEET-PG High-Yield Pearls:** * **Disulfiram-like reaction** can also be caused by other drugs: **Metronidazole** (most common), Cefotetan, Griseofulvin, and Sulfonylureas [1]. * **Acamprosate** is the drug of choice for patients with **liver disease** (as it is renally excreted) [1]. * **Naltrexone** is the drug of choice to **reduce craving** and is contraindicated in patients with acute hepatitis or liver failure [1]. * **Topiramate** and **Baclofen** are other emerging agents used to reduce alcohol consumption.

Question 306: A 35-year-old female presents for smoking cessation. She was diagnosed with depression two years ago and took SSRIs for six months, but has been off medication for 1.5 years and is currently mentally healthy. She started smoking at age 25 and has attempted to quit multiple times using nicotine gum, but has been unable to sustain abstinence for more than one month. What is the best recommendation for this patient?

A. Counseling only
B. Bupropion plus nicotine patches
C. Varenicline orally
D. Counseling plus varenicline (Correct Answer)

Explanation: ### Explanation **1. Why Option D is Correct:** The management of smoking cessation is most effective when combining **pharmacotherapy with behavioral counseling**. According to clinical guidelines, the combination significantly increases long-term abstinence rates compared to either intervention alone. **Varenicline** is a partial agonist at the **α4β2 nicotinic acetylcholine receptor**. It works by reducing withdrawal symptoms (agonist effect) and blocking the rewarding effects of nicotine if the patient relapses (antagonist effect). It is currently considered the **first-line** pharmacological agent for smoking cessation, often showing superior efficacy compared to Bupropion or Nicotine Replacement Therapy (NRT) monotherapy. **2. Why Other Options are Incorrect:** * **Option A (Counseling only):** While essential, counseling alone has lower success rates than when combined with pharmacotherapy, especially in a patient who has already failed multiple self-attempts. * **Option B (Bupropion + Patches):** While this combination is effective, Varenicline is generally preferred as the initial choice. Furthermore, although this patient is currently stable, Bupropion is often avoided if there is a risk of lowering the seizure threshold, though it is not strictly contraindicated here. * **Option C (Varenicline orally):** This provides the drug but ignores the synergistic benefit of behavioral counseling, which is the "Gold Standard" approach. **3. High-Yield Clinical Pearls for NEET-PG:** * **Varenicline Side Effects:** The most common side effect is **nausea** (minimized by taking it with food/water). Previously, there were concerns regarding neuropsychiatric events (suicidal ideation), but recent large-scale studies (EAGLES trial) have shown it is safe even in patients with stable psychiatric histories. * **Bupropion Contraindications:** History of seizures, eating disorders (anorexia/bulimia), or recent MAO inhibitor use. * **Nicotine Withdrawal:** Symptoms peak within 24–48 hours and include irritability, anxiety, increased appetite, and insomnia. * **The "5 As" Model:** Ask, Advise, Assess, Assist, and Arrange.

Question 307: Hallucinations are primarily produced by which of the following substances?

A. Lysergic acid diethylamide (LSD) (Correct Answer)
B. Morphine
C. Paroxetine
D. Chlorpromazine

Explanation: **Explanation:** The correct answer is **Lysergic acid diethylamide (LSD)**. LSD is a potent **hallucinogen** (psychedelic) that primarily acts as a partial agonist at the **5-HT2A receptors** in the central nervous system. This serotonergic stimulation leads to profound alterations in sensory perception, most notably **visual hallucinations**, "synesthesia" (hearing colors or seeing sounds), and distortions of time and space. **Analysis of Options:** * **Morphine (Option B):** An opioid analgesic that acts on mu-opioid receptors. Its primary effects include analgesia, euphoria, and respiratory depression. While "toxic psychosis" can occur in rare cases of withdrawal or overdose, it is not classified as a primary hallucinogen. * **Paroxetine (Option C):** A Selective Serotonin Reuptake Inhibitor (SSRI) used as an antidepressant and anxiolytic. It increases synaptic serotonin levels but does not typically cause hallucinations at therapeutic doses. * **Chlorpromazine (Option D):** A typical (first-generation) antipsychotic that acts as a D2 receptor antagonist. It is used to **treat** hallucinations and psychosis, rather than produce them. **High-Yield Clinical Pearls for NEET-PG:** * **LSD "Bad Trip":** Characterized by acute panic, anxiety, and terrifying hallucinations. The management of choice is reassurance ("talking down") and **Benzodiazepines**. * **Flashbacks:** Also known as **Hallucinogen Persisting Perception Disorder (HPPD)**, where the user re-experiences the drug's effects weeks or months after the last use. * **Pupillary Sign:** LSD intoxication typically presents with **Mydriasis** (dilated pupils), whereas Morphine (Opioids) causes **Miosis** (pinpoint pupils). * **Psilocybin (Magic Mushrooms) and Mescaline (Peyote)** are other common hallucinogens that share a similar mechanism with LSD.

Question 308: Which of the following is a symptom of opioid withdrawal?

A. Vomiting (Correct Answer)
B. Delirium
C. Constipation
D. Miosis

Explanation: **Explanation:** Opioid withdrawal occurs when a chronic user abruptly stops or reduces intake. Opioids are CNS depressants that slow down bodily functions; therefore, withdrawal is characterized by **autonomic hyperactivity** and a "rebound" of the systems previously suppressed. **1. Why Vomiting is Correct:** Opioids typically cause constipation and decrease GI motility. During withdrawal, the GI tract becomes hyperactive, leading to **nausea, vomiting, abdominal cramps, and diarrhea**. This is a hallmark sign of the body attempting to restore equilibrium. **2. Why Incorrect Options are Wrong:** * **Delirium:** This is characteristic of **Alcohol withdrawal** (Delirium Tremens) or sedative-hypnotic withdrawal. Opioid withdrawal, while extremely distressing ("flu-like" symptoms), is rarely life-threatening and does not typically cause delirium. * **Constipation:** This is a classic side effect of **opioid intoxication** or chronic use. In withdrawal, the opposite occurs (diarrhea). * **Miosis (Pinpoint pupils):** This is a pathognomonic sign of **opioid poisoning/intoxication**. In withdrawal, the pupils undergo **Mydriasis** (dilation) due to sympathetic overactivity. **Clinical Pearls for NEET-PG:** * **Mnemonic for Opioid Withdrawal:** Think of "Flu-like symptoms" + **"Dripping from every orifice"** (Rhinorrhea, Lacrimation, Diarrhea, Vomiting, Sweating). * **Piloerection:** (Goosebumps) is a highly specific sign of opioid withdrawal (origin of the term "cold turkey"). * **Treatment:** The drug of choice for managing withdrawal symptoms is **Clonidine** (alpha-2 agonist) or substitution therapy with **Methadone/Buprenorphine**. * **Pupillary status:** Always remember: Intoxication = Miosis; Withdrawal = Mydriasis.

Question 309: A 40-year-old chronic alcoholic presents to the emergency room with acute onset of visual hallucinations (seeing snakes), failure to recognize family members, violent behavior, and tremulousness for a few hours. The patient has abstained from alcohol for 2 days. Examination reveals elevated blood pressure, tremors, increased psychomotor activity, fearful affect, hallucinatory behavior, disorientation, and impaired judgment and insight. What is the most likely diagnosis?

A. Alcoholic hallucinosis
B. Delirium tremens (Correct Answer)
C. Wernicke encephalopathy
D. Korsakoff psychosis

Explanation: **Explanation:** The patient is presenting with **Delirium Tremens (DT)**, the most severe form of alcohol withdrawal. The diagnosis is confirmed by the triad of **clouding of consciousness (disorientation)**, **autonomic hyperactivity** (elevated BP, tremors), and **perceptual disturbances** (visual hallucinations). DT typically occurs 48–96 hours after the last drink. The presence of disorientation and autonomic instability is the key differentiator from other withdrawal states. **Why other options are incorrect:** * **Alcoholic Hallucinosis:** Occurs within 12–24 hours of abstinence. Crucially, it occurs in a state of **clear sensorium** (the patient is oriented) and lacks significant autonomic instability. Hallucinations are usually auditory. * **Wernicke Encephalopathy:** Caused by Thiamine (B1) deficiency. It presents with the triad of **Ophthalmoplegia/Ataxia/Confusion**. While confusion is present, it lacks the acute autonomic surge and vivid visual hallucinations seen here. * **Korsakoff Psychosis:** A chronic sequel of Wernicke’s characterized by **anterograde amnesia** and **confabulation** (making up stories to fill memory gaps). It is not an acute withdrawal phenomenon. **High-Yield Pearls for NEET-PG:** * **Timeline:** Minor withdrawal (6-12h) → Seizures (12-48h) → Hallucinosis (12-24h) → **DT (48-96h)**. * **Mortality:** DT is a medical emergency with a mortality rate of up to 5% (usually due to arrhythmia or respiratory failure). * **Drug of Choice:** **Benzodiazepines** (Chlordiazepoxide or Diazepam). In patients with liver failure, use **LOT** (Lorazepam, Oxazepam, Temazepam) as they lack active metabolites. * **Visual Hallucinations:** Often involve small animals or insects (**Lilliputian hallucinations**).

Question 310: Which of the following is false regarding delirium tremens?

A. Tremors
B. Opthalmoplegia (Correct Answer)
C. Visual hallucination
D. Clouding of consciousness

Explanation: **Explanation:** **Delirium Tremens (DT)** is the most severe form of alcohol withdrawal, typically occurring 48–96 hours after the last drink. It is a medical emergency characterized by autonomic hyperactivity and altered sensorium. **Why Opthalmoplegia is the correct (False) answer:** **Ophthalmoplegia** (paralysis of ocular muscles) is a classic feature of **Wernicke’s Encephalopathy**, not Delirium Tremens. Wernicke’s is caused by Thiamine (Vitamin B1) deficiency and is characterized by the triad of Global Confusion, Ataxia, and Ophthalmoplegia (specifically nystagmus or abducens nerve palsy). While both conditions are associated with chronic alcohol use, they are distinct clinical entities. **Analysis of other options:** * **A. Tremors:** Coarse tremors are a hallmark of alcohol withdrawal. In DT, these are often associated with other signs of autonomic hyperactivity like tachycardia, hypertension, and diaphoresis. * **C. Visual Hallucinations:** These are very common in DT. They are often vivid and terrifying (e.g., seeing small animals or insects, known as *micropsia* or *lilliputian hallucinations*). * **D. Clouding of Consciousness:** DT is defined by a "delirium," which implies a disturbance in consciousness, disorientation (to time, place, and person), and impaired attention. **High-Yield Clinical Pearls for NEET-PG:** * **Timeframe:** DT typically peaks at **72–96 hours** after cessation of alcohol. * **Mortality:** If untreated, DT has a mortality rate of up to 20% (usually due to arrhythmias or respiratory failure). * **Drug of Choice:** **Benzodiazepines** (e.g., Diazepam, Lorazepam) are the gold standard for management. * **Risk Factors:** History of prior DT, age >30, and concurrent medical illness. * **Alcoholic Hallucinosis vs. DT:** Unlike DT, Alcoholic Hallucinosis occurs within 12–24 hours, features auditory hallucinations, and presents with a **clear sensorium** (no clouding of consciousness).

Practice by Chapter

Neurobiology of Addiction

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Alcohol Use Disorder

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Opioid Use Disorder

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Cannabis Use Disorder

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Stimulant Use Disorders

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Sedative, Hypnotic, and Anxiolytic Use Disorders

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Tobacco Use Disorder

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Hallucinogen-Related Disorders

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Substance Withdrawal Syndromes

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Pharmacotherapy for Substance Use Disorders

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Psychosocial Interventions

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Dual Diagnosis Management

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