Adverse drug reactions MCQs With Answer

Introduction

Adverse drug reactions MCQs With Answer provide B. Pharm students a focused, practical approach to understanding ADR types, mechanisms, detection, and prevention. This concise guide emphasizes pharmacovigilance, ADR classification (Type A and B), immunologic hypersensitivity, dose-related toxicity, idiosyncratic reactions, and common severe events such as hepatotoxicity, Stevens–Johnson syndrome, and agranulocytosis. Key concepts include causality assessment tools (e.g., Naranjo scale), reporting systems, monitoring parameters, risk factors, and strategies for management and rechallenge. These MCQs help build clinical judgment, reporting competence, and safe medication use essential for pharmacists. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which classification of adverse drug reactions is predictable and related to the pharmacologic action of the drug?

  • Type A reactions — dose-dependent and predictable
  • Type B reactions — unpredictable and idiosyncratic
  • Type C reactions — chronic reactions
  • Type D reactions — delayed reactions

Correct Answer: Type A reactions — dose-dependent and predictable

Q2. Which tool is commonly used for systematic causality assessment of adverse drug reactions?

  • RUCAM scale
  • Naranjo algorithm
  • Glasgow coma scale
  • APACHE II score

Correct Answer: Naranjo algorithm

Q3. A patient develops a widespread blistering rash after taking sulfonamides; the most severe diagnosis to consider is:

  • Urticaria
  • Fixed drug eruption
  • Stevens–Johnson syndrome / Toxic epidermal necrolysis
  • Exanthematous drug eruption

Correct Answer: Stevens–Johnson syndrome / Toxic epidermal necrolysis

Q4. Which adverse drug reaction is most likely immune-mediated and often occurs on re-exposure to the drug?

  • Type A reaction
  • Type B reaction
  • Type A dose toxicity
  • Pharmacokinetic interaction

Correct Answer: Type B reaction

Q5. Which laboratory abnormality is most characteristic of drug-induced hepatocellular injury?

  • Isolated alkaline phosphatase elevation
  • Marked elevation of ALT and AST
  • Elevated amylase
  • Hypokalemia

Correct Answer: Marked elevation of ALT and AST

Q6. What is the primary purpose of pharmacovigilance systems?

  • To market new drugs
  • To detect, assess, understand, and prevent adverse effects and other drug-related problems
  • To regulate drug prices
  • To test drug efficacy in randomized trials

Correct Answer: To detect, assess, understand, and prevent adverse effects and other drug-related problems

Q7. Which adverse effect is classically associated with prolonged use of aminoglycosides?

  • Hepatotoxicity
  • Nephrotoxicity and ototoxicity
  • Cardiac arrhythmia
  • Pancytopenia

Correct Answer: Nephrotoxicity and ototoxicity

Q8. Fixed drug eruption typically presents as which of the following?

  • Linear streaks along dermatomes
  • Recurrent well-demarcated round or oval pigmented lesions at the same site
  • Diffuse urticaria resolving with antihistamines
  • Pustular lesions on palms and soles only

Correct Answer: Recurrent well-demarcated round or oval pigmented lesions at the same site

Q9. Which adverse reaction classification reflects events related to cumulative dose or long-term therapy?

  • Type A
  • Type B
  • Type C
  • Type E

Correct Answer: Type C

Q10. Which is the best immediate management step for a suspected anaphylactic reaction to a drug?

  • Oral antihistamine only
  • Intramuscular epinephrine and supportive care
  • Wait and observe
  • Start oral corticosteroids only

Correct Answer: Intramuscular epinephrine and supportive care

Q11. Which drug is most commonly associated with drug-induced agranulocytosis?

  • Metformin
  • Clozapine
  • Omeprazole
  • Hydrochlorothiazide

Correct Answer: Clozapine

Q12. Which term describes an adverse reaction preventable by dose adjustment, monitoring, or avoiding interactions?

  • Type B unpredictable
  • Preventable ADR
  • Idiosyncratic ADR
  • Intrinsic ADR

Correct Answer: Preventable ADR

Q13. Which mechanism is responsible for most Type A adverse drug reactions?

  • Allergic immune response
  • Exaggeration of known pharmacologic effect
  • Genetic enzyme deficiency causing immune complex formation
  • Idiosyncratic mitochondrial toxicity

Correct Answer: Exaggeration of known pharmacologic effect

Q14. For suspected drug-induced liver injury, which is an important clinical action?

  • Continue drug and re-evaluate in 6 months
  • Stop the suspected drug and monitor liver enzymes
  • Start broad-spectrum antibiotics immediately
  • Ignore transaminase rises if bilirubin is normal

Correct Answer: Stop the suspected drug and monitor liver enzymes

Q15. Which adverse reaction often shows eosinophilia and involves fever, rash, and organ involvement after drug exposure?

  • Acute generalized exanthematous pustulosis (AGEP)
  • DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms)
  • Fixed drug eruption
  • Type A dose-related toxicity

Correct Answer: DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms)

Q16. Which pharmacokinetic factor commonly increases risk of adverse drug reactions in the elderly?

  • Increased renal clearance
  • Decreased hepatic metabolism and renal excretion
  • Faster gastric emptying
  • Increased total body water for lipophilic drugs

Correct Answer: Decreased hepatic metabolism and renal excretion

Q17. Cross-reactivity between penicillins and which antibiotic class is a key consideration in hypersensitivity?

  • Macrolides
  • Carbapenems
  • Tetracyclines
  • Fluoroquinolones

Correct Answer: Carbapenems

Q18. Which adverse event is most characteristic of statin therapy and requires monitoring of creatine kinase (CK)?

  • Interstitial lung disease
  • Myopathy and rhabdomyolysis
  • QT prolongation
  • Agranulocytosis

Correct Answer: Myopathy and rhabdomyolysis

Q19. What does a positive dechallenge mean in ADR assessment?

  • Symptoms worsen after stopping the drug
  • Adverse event improves after stopping the drug
  • Adverse event appears only on re-exposure
  • Adverse event is unrelated to the drug

Correct Answer: Adverse event improves after stopping the drug

Q20. Which monitoring is essential when initiating warfarin to reduce adverse reactions?

  • Serum potassium
  • INR (International Normalized Ratio)
  • Blood glucose
  • Serum amylase

Correct Answer: INR (International Normalized Ratio)

Q21. Which antibiotic class is most commonly associated with Clostridioides difficile-associated diarrhea as an ADR?

  • Beta-lactams and fluoroquinolones
  • Macrolides
  • Tetracyclines only
  • Glycopeptides only

Correct Answer: Beta-lactams and fluoroquinolones

Q22. Which adverse reaction category includes drug withdrawal syndromes?

  • Type A — dose related
  • Type D — time related (delayed)
  • Type E — withdrawal reactions
  • Type F — failure of therapy

Correct Answer: Type E — withdrawal reactions

Q23. Which organ system is most commonly involved in serious idiosyncratic drug reactions causing mortality?

  • Cardiovascular system
  • Liver
  • Musculoskeletal system
  • Eye

Correct Answer: Liver

Q24. When is rechallenge with a suspect drug contraindicated?

  • When the initial reaction was mild rash
  • When the reaction was life-threatening such as Stevens–Johnson syndrome
  • When the drug is critical and no alternatives exist
  • When monitoring is available

Correct Answer: When the reaction was life-threatening such as Stevens–Johnson syndrome

Q25. Which adverse effect is a hallmark of opioid overdose?

  • Chest pain
  • Respiratory depression and miosis
  • Hypertension and tachycardia
  • Paresthesia without respiratory symptoms

Correct Answer: Respiratory depression and miosis

Q26. What is the preferred immediate reporting action for a serious unexpected ADR in pharmacovigilance?

  • Ignore if rare
  • Submit a timely report to national pharmacovigilance center or regulatory authority
  • Only inform the patient verbally
  • Wait until publication of case series

Correct Answer: Submit a timely report to national pharmacovigilance center or regulatory authority

Q27. Which class of drugs is commonly implicated in QT interval prolongation and risk of torsades de pointes?

  • SSRIs and some antipsychotics
  • Beta-lactam antibiotics
  • Nonsteroidal anti-inflammatory drugs
  • Histamine H2 blockers only

Correct Answer: SSRIs and some antipsychotics

Q28. A child develops hemolytic anemia after exposure to primaquine; the most likely predisposing factor is:

  • Renal failure
  • G6PD deficiency
  • Vitamin D deficiency
  • Pyridoxine excess

Correct Answer: G6PD deficiency

Q29. Which statement about idiosyncratic drug reactions is true?

  • They are dose predictable and common
  • They are rare, unpredictable, and often immune or metabolic in origin
  • They only occur with overdoses
  • They can be prevented by simple dose reduction in all cases

Correct Answer: They are rare, unpredictable, and often immune or metabolic in origin

Q30. Which preventive strategy reduces the risk of ADRs due to drug–drug interactions?

  • Ignoring patient medication history
  • Performing medication reconciliation and checking interaction databases
  • Prescribing multiple drugs without review
  • Avoiding monitoring of serum drug levels when indicated

Correct Answer: Performing medication reconciliation and checking interaction databases

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