Substance Use Disorders (Alcohol, Opioids, Other Substances) MCQs

Psychiatry · 55 free questions with answers & explanations.

1. A 45-year-old man with chronic alcohol use disorder is admitted for elective surgery. On post-operative day two he develops tremors, diaphoresis, tachycardia, and visual hallucinations of insects crawling on the walls. He is agitated and disoriented. His BP is 160/100 mmHg. What is the most appropriate immediate pharmacological treatment?
2. A 28-year-old man on methadone maintenance therapy for opioid use disorder is brought to the emergency department unresponsive with miosis and respiratory rate of 6 breaths per minute. Which feature distinguishes a methadone overdose from that of shorter-acting opioids in terms of clinical management?
3. A 35-year-old woman with alcohol use disorder has been abstinent for two months. She is started on a medication that causes severe flushing, palpitations, nausea, and vomiting if she consumes any alcohol. Which enzyme does this drug inhibit?
4. A 22-year-old presents to the emergency department after smoking cannabis for the first time. He is severely anxious, experiences derealization, and believes the nurses are monitoring him for the government. His vital signs show tachycardia and mild hypertension. He has no prior psychiatric history. Urine toxicology is positive only for THC. What is the expected course?
5. Buprenorphine-naloxone (Suboxone) is prescribed for a patient with opioid use disorder. The naloxone component is included primarily for which reason?
6. A 45-year-old man with alcohol dependence is admitted for detoxification. On day 3, he develops confusion, ophthalmoplegia, ataxia, and peripheral neuropathy. He has been receiving glucose infusions. What is the immediate treatment?
7. A 30-year-old heroin-dependent patient is started on methadone maintenance therapy. After 2 weeks at 80 mg/day, he is brought unconscious with a QTc of 560 ms on ECG. What is the most important electrolyte/investigation to check urgently?
8. Which of the following statements about naltrexone in alcohol use disorder (AUD) is most accurate?
9. A 28-year-old man is brought to the emergency with agitation, tachycardia (HR 130/min), hypertension, hyperthermia, diaphoresis, dilated pupils, and hyperreflexia with lower limb clonus after using multiple recreational drugs. Which diagnosis and antidote combination is correct?
10. In the management of opioid withdrawal, which medication works by reducing noradrenergic hyperactivity from the locus coeruleus and alleviates symptoms such as piloerection, diaphoresis, and lacrimation?
11. A 42-year-old chronic alcohol-dependent man is admitted for detoxification. On day 3, he develops confusion, ataxia, and horizontal nystagmus. The most likely diagnosis and the IMMEDIATE treatment is:
12. A patient on buprenorphine/naloxone (Suboxone) maintenance presents in acute pain after fracturing his femur. The anaesthesiologist asks about opioid management intraoperatively. The most appropriate intraoperative analgesia strategy is:
13. Disulfiram (Antabuse) works by inhibiting which enzyme, leading to acetaldehyde accumulation when alcohol is consumed?
14. Naltrexone reduces alcohol craving and relapse primarily through which mechanism?
15. A 30-year-old heroin addict is found unconscious with pinpoint pupils, bradycardia, and respiratory rate 6/min. After two doses of IV naloxone he wakes up, but 45 minutes later lapses back into coma. The BEST explanation for this recurrence is:
16. A 45-year-old chronic alcohol user is admitted for alcohol detoxification. On day 2, he develops visual hallucinations, confusion, and a seizure. His pulse is 120/min, BP 160/95, and he is diaphoretic. What is the IMMEDIATE treatment of choice?
17. A 30-year-old heroin-dependent man is started on methadone maintenance therapy. After 2 weeks on a stable dose, he reports craving reduction but is discovered to have used heroin once. The urine toxicology confirms heroin use. According to opioid use disorder deaddiction principles, what is the CORRECT action?
18. A 28-year-old presents after taking a recreational substance. He shows hyperreflexia, diaphoresis, tremor, agitation, diarrhea, mydriasis, and hyperthermia. His pulse is 130/min. He is on an SSRI for depression. Which substance is MOST likely responsible, and what is the mechanism?
19. Disulfiram (Antabuse) for alcohol use disorder works by inhibiting which enzyme, leading to accumulation of acetaldehyde?
20. A 22-year-old college student is brought to the ER after intravenous heroin overdose. He is unresponsive with a respiratory rate of 4/min, pinpoint pupils, and cyanosis. What is the CORRECT naloxone dosing strategy?
21. A 40-year-old chronic alcoholic presents with confusion, ophthalmoplegia, and ataxia. He is treated with IV thiamine. After partial improvement, he is noted to have anterograde amnesia and confabulation. Which specific structural lesion explains the persistent amnestic syndrome?
22. A 28-year-old male heroin-dependent patient has been stable on methadone maintenance 80 mg/day for 6 months. He is now admitted for emergency cholecystectomy. Post-operatively, he develops severe agitation, piloerection, rhinorrhoea, and hypertension on day 2. Methadone was not given peri-operatively. What is the most appropriate immediate management?
23. In alcohol use disorder deaddiction, acamprosate is preferred over disulfiram in which clinical situation?
24. A patient presents with euphoria, conjunctival injection, increased appetite, impaired short-term memory, and slowed reaction time 2 hours after cannabis use. Urine drug screen is positive for cannabinoids. Which receptor mechanism mediates the psychoactive effects?
25. Buprenorphine/naloxone (Suboxone) is the preferred formulation over buprenorphine alone for opioid use disorder treatment. The naloxone component serves which specific pharmacological purpose?
26. A 38-year-old chronic alcohol user is admitted with a generalised tonic-clonic seizure on day 2 of abstinence. He develops tremors, diaphoresis, tachycardia, and hypertension. The mechanism of alcohol withdrawal seizures is best explained by:
27. A patient with opioid use disorder is being managed with buprenorphine-naloxone (Suboxone). He presents 6 hours after his last buprenorphine dose with severe withdrawal symptoms. The most likely reason is:
28. An alcoholic patient treated with disulfiram ingests a small quantity of alcohol and develops severe flushing, palpitations, nausea, and hypotension. The biochemical mechanism of this reaction involves accumulation of which compound?
29. Which AUDIT-C score in a 45-year-old male is the validated threshold recommended to trigger brief intervention for hazardous alcohol use in primary care settings?
30. A 24-year-old opioid use disorder patient on stable methadone maintenance presents with QTc of 540 ms on ECG. The most appropriate management step is:
31. A 35-year-old presents with pinpoint pupils, bradycardia, respiratory rate of 6/min, and Glasgow Coma Scale of 8. He responds rapidly and fully to IV naloxone. The most critical clinical consideration when managing this patient is:
32. A patient recovering from alcohol dependence is started on acamprosate. Its mechanism of action for reducing cravings is:
33. A 38-year-old chronic alcoholic is admitted for elective surgery. He is given diazepam 20 mg TDS for alcohol withdrawal prophylaxis. On day 3, he becomes confused, disoriented, febrile (38.2°C), grossly tremulous, and develops vivid visual hallucinations of insects crawling on him. He then has a generalised tonic-clonic seizure. This clinical picture is consistent with:
34. A 25-year-old heroin user presents in opioid withdrawal with lacrimation, rhinorrhoea, yawning, piloerection, mydriasis, and diarrhoea scoring 24 on COWS. He requests medication. Which agent specifically addresses the noradrenergic-mediated symptoms of opioid withdrawal?
35. A 42-year-old man with chronic heavy alcohol use is admitted with Wernicke's encephalopathy. Which is the most important IMMEDIATE treatment?
36. A 28-year-old heroin-dependent man is being considered for opioid substitution therapy (OST). He has previously failed three detoxification attempts. Which agent used in OST acts as a partial agonist at the mu-opioid receptor and reduces illicit opioid use with better safety profile than methadone in overdose?
37. Alcohol withdrawal seizures typically occur within what time window after the last drink, and which drug is first-line treatment to prevent them in high-risk patients?
38. A 40-year-old chronic alcohol user is admitted with tremors, sweating, and elevated BP. After 24 hours of abstinence, he develops a generalised tonic-clonic seizure. Which GABA-A receptor change underlies this seizure?
39. A 28-year-old opioid-dependent patient on buprenorphine maintenance is admitted for a surgical procedure requiring post-operative analgesia. What is the CORRECT analgesic approach?
40. A patient presents with dilated pupils, diaphoresis, piloerection, abdominal cramps, diarrhoea, and myalgia 12 hours after stopping heroin. The physiological mechanism of these symptoms is:
41. Disulfiram works by inhibiting aldehyde dehydrogenase. When alcohol is consumed with disulfiram, which metabolite accumulates causing the flushing, nausea, and vomiting reaction?
42. A 40-year-old chronic alcoholic presents at 48 hours of abstinence with tremors, sweating, hypertension, tachycardia, and visual hallucinations. He is oriented to time and place. CIWA-Ar score is 22. Which is the MOST appropriate treatment?
43. A 30-year-old heroin addict is initiated on buprenorphine-naloxone for opioid use disorder. He receives his first dose 18 hours after his last heroin use. Why is naloxone included in the sublingual formulation?
44. Wernicke's encephalopathy in a chronic alcoholic is precipitated by glucose administration without prior thiamine in patients with thiamine deficiency. The classic triad consists of which three features?
45. A patient abusing cocaine presents to the ER with chest pain. ECG shows ST elevation in leads II, III, aVF. Which medication used commonly for myocardial infarction is RELATIVELY CONTRAINDICATED in cocaine-induced acute coronary syndrome?
46. A 45-year-old chronic heavy alcohol user is admitted following a road traffic accident. On admission he is oriented and his blood alcohol level is 220 mg/dL. Fourteen hours later he develops tremors, agitation, diaphoresis, and a generalized tonic-clonic seizure. His blood pressure is 170/100 mmHg and heart rate is 112/min. What is the mainstay pharmacological treatment for this condition?
47. A 28-year-old man dependent on heroin is enrolled in a medication-assisted treatment program. He is started on a medication that, at therapeutic doses, occupies opioid receptors without producing significant euphoria and blocks the effects of additional opioid use, thus discouraging craving-driven use. Which medication is being described?
48. A 19-year-old college student is brought to the emergency department after ingesting an unknown substance at a party. He has dilated pupils, tachycardia, hypertension, diaphoresis, and is extremely agitated. He is seeing geometric visual hallucinations and reports the walls are 'breathing.' His temperature is 37.4°C and toxicology screen is positive only for the substance in question. Which substance is most likely responsible?
49. A 52-year-old man with alcohol use disorder has been abstinent for 6 months after completing detoxification. He is motivated to maintain sobriety but continues to experience strong cravings. He has no liver disease. Which pharmacological agent reduces craving by modulating central glutamate and GABA transmission and is approved for maintaining alcohol abstinence?
50. A 23-year-old woman who regularly smokes cannabis presents to a psychiatry clinic. She reports that over the past year she has needed to use substantially more cannabis to achieve the same effect, and when she tries to stop she becomes irritable, restless, has disturbed sleep, and decreased appetite. These withdrawal symptoms resolve when she resumes use. How many criteria from the DSM-5-TR substance use disorder list must be present over a 12-month period for a diagnosis of 'severe' cannabis use disorder?
51. A 38-year-old man is brought to the emergency department confused and agitated. He works at a chemical plant and accidentally inhaled a large amount of industrial solvent. Examination reveals slurred speech, ataxia, nystagmus, and perioral rash. He is tachycardic and his ECG shows a prolonged QTc. His blood alcohol level is undetectable. Which substance class is most likely responsible?
52. A 50-year-old chronic alcohol user is motivated to stop. He has no liver disease. Which pharmacological agent for alcohol use disorder works by REDUCING alcohol CRAVING through mu-opioid receptor blockade?
53. A 35-year-old opioid-dependent patient is being considered for buprenorphine-naloxone (Suboxone) therapy. Why is naloxone included in the sublingual formulation?
54. A 22-year-old is brought to the ER after smoking a synthetic cannabinoid ('spice'). He is severely agitated, has a temperature of 39.5°C, HR 145/min, BP 185/110, and is hallucinating. Unlike natural cannabis, synthetic cannabinoids cause more severe toxicity because:
55. The Prochaska and DiClemente Transtheoretical Model (Stages of Change) is used in deaddiction counselling. A patient with alcohol use disorder says: 'Yes, I know my drinking is a problem and I'm planning to do something about it within the next month.' Which stage is he in?