Antiemetic therapy and nausea management in oncology MCQs With Answer

Antiemetic therapy and nausea management are critical components of supportive care in oncology, directly impacting patient comfort, treatment adherence, and quality of life. This blog presents focused multiple-choice questions tailored for M.Pharm students to deepen understanding of pathophysiology, receptor pharmacology, guideline-based prophylaxis, and practical drug selection for acute, delayed, anticipatory, and breakthrough chemotherapy-induced nausea and vomiting (CINV). The questions emphasize mechanisms of action, combination regimens (5-HT3 RAs, NK1 RAs, corticosteroids, olanzapine), adverse effects, drug interactions, and special situations like multiday chemotherapy or opioid-induced nausea. Use these MCQs to refine clinical reasoning and prepare for examinations in Pharmacotherapeutics II.

Q1. Which neurotransmitter and receptor are primarily responsible for acute chemotherapy-induced nausea and vomiting?

• Histamine acting at H1 receptors
• Dopamine acting at D2 receptors
• Serotonin acting at 5-HT3 receptors
• Substance P acting at NK1 receptors

Correct Answer: Serotonin acting at 5-HT3 receptors

Q2. Which drug class is most effective as first-line prophylaxis for acute CINV?

• Neurokinin-1 (NK1) receptor antagonists
• 5-HT3 receptor antagonists (e.g., ondansetron)
• Cannabinoid receptor agonists (e.g., dronabinol)
• Benzodiazepines (e.g., lorazepam)

Correct Answer: 5-HT3 receptor antagonists (e.g., ondansetron)

Q3. What is the primary mechanism of action of NK1 receptor antagonists like aprepitant in CINV?

• Blockade of dopamine D2 receptors in the chemoreceptor trigger zone
• Central GABA-A receptor potentiation to reduce anxiety-related nausea
• Blockade of substance P at neurokinin-1 (NK1) receptors
• Peripheral motility enhancement via muscarinic receptor agonism

Correct Answer: Blockade of substance P at neurokinin-1 (NK1) receptors

Q4. Which single agent is most commonly used to prevent delayed CINV?

• Ondansetron
• Dexamethasone
• Metoclopramide
• Diphenhydramine

Correct Answer: Dexamethasone

Q5. For highly emetogenic chemotherapy, which combination is recommended by guidelines for prophylaxis?

• Ondansetron alone
• NK1 RA + dopamine antagonist
• 5-HT3 RA + NK1 RA + dexamethasone (with/without olanzapine)
• Cannabinoid + benzodiazepine

Correct Answer: 5-HT3 RA + NK1 RA + dexamethasone (with/without olanzapine)

Q6. How does olanzapine contribute to control of refractory or highly emetogenic CINV?

• Selective 5-HT3 antagonism only
• Peripheral opioid receptor blockade
• Antagonism at multiple receptors including dopamine, serotonin (5-HT2/3), histamine and muscarinic receptors
• Pure cannabinoid receptor agonism

Correct Answer: Antagonism at multiple receptors including dopamine, serotonin (5-HT2/3), histamine and muscarinic receptors

Q7. What is the principal pharmacologic action of metoclopramide relevant to antiemetic therapy?

• 5-HT3 receptor antagonism only
• Central dopamine D2 receptor antagonism and prokinetic 5-HT4 agonist activity
• NK1 receptor antagonism
• GABA-B receptor agonism

Correct Answer: Central dopamine D2 receptor antagonism and prokinetic 5-HT4 agonist activity

Q8. Dronabinol and nabilone exert antiemetic effects primarily through which mechanism?

• 5-HT3 receptor antagonism in the gut
• Agonism of central cannabinoid CB1 receptors
• Blockade of peripheral substance P
• Muscarinic receptor antagonism in the vestibular system

Correct Answer: Agonism of central cannabinoid CB1 receptors

Q9. Which significant cardiac adverse effect is associated with many 5-HT3 receptor antagonists and requires monitoring?

• Torsades de pointes due to QT interval prolongation
• Marked hypertension
• Ventricular fibrillation unrelated to QT
• Atrioventricular block without QT changes

Correct Answer: Torsades de pointes due to QT interval prolongation

Q10. Which medication is most useful for anticipatory nausea related to prior chemotherapy sessions?

• Olanzapine
• Lorazepam
• Aprepitant
• Ondansetron

Correct Answer: Lorazepam

Q11. For breakthrough CINV despite prophylaxis, what is the recommended initial strategy?

• Switch to the same class used for prophylaxis at a higher dose
• Use a rescue agent from a different pharmacologic class, e.g., metoclopramide or haloperidol
• Stop all antiemetics and observe
• Only increase fluids without pharmacologic therapy

Correct Answer: Use a rescue agent from a different pharmacologic class, e.g., metoclopramide or haloperidol

Q12. How is “highly emetogenic” chemotherapy defined in terms of risk of emesis without prophylaxis?

• 10–30% risk of emesis
• 30–60% risk of emesis
• 60–90% risk of emesis
• >90% risk of emesis without prophylaxis

Correct Answer: >90% risk of emesis without prophylaxis

Q13. When added to a 5-HT3 antagonist and dexamethasone, what benefit does an NK1 receptor antagonist provide?

• Reduces only anticipatory nausea
• Improves prevention of delayed CINV when added to 5-HT3 RA and dexamethasone
• Increases prokinetic activity in the gut
• Replaces the need for dexamethasone entirely

Correct Answer: Improves prevention of delayed CINV when added to 5-HT3 RA and dexamethasone

Q14. Which antiemetic class is most commonly associated with extrapyramidal symptoms (EPS)?

• 5-HT3 receptor antagonists
• Dopamine D2 receptor antagonists such as metoclopramide
• Cannabinoids
• Benzodiazepines

Correct Answer: Dopamine D2 receptor antagonists such as metoclopramide

Q15. Selective 5-HT3 receptor antagonists are generally least effective for which type of nausea?

• Chemotherapy-induced nausea
• Postoperative nausea and vomiting
• Motion sickness (vestibular-mediated nausea)
• Acute CINV from cisplatin

Correct Answer: Motion sickness (vestibular-mediated nausea)

Q16. Which clinically important drug interaction is associated with aprepitant?

• Strong inhibition of CYP2D6 causing QT prolongation
• Moderate CYP3A4 inhibition leading to interaction with dexamethasone and some chemotherapy agents
• Complete inhibition of P-glycoprotein increasing all opioid levels
• No significant interactions due to inert metabolism

Correct Answer: Moderate CYP3A4 inhibition leading to interaction with dexamethasone and some chemotherapy agents

Q17. Which antiemetic also has appetite-stimulating properties and may be considered in cachectic oncology patients?

• Ondansetron
• Dronabinol (synthetic THC)
• Metoclopramide
• Prochlorperazine

Correct Answer: Dronabinol (synthetic THC)

Q18. In which clinical scenario is metoclopramide contraindicated or used with extreme caution?

• Functional dyspepsia without obstruction
• Mechanical bowel obstruction
• Postoperative ileus with clear evidence of obstruction
• Migraine-associated nausea

Correct Answer: Mechanical bowel obstruction

Q19. What is the most appropriate class of antiemetic for opioid-induced nausea in a cancer patient?

• 5-HT3 antagonists as first-line for opioid-related nausea
• Dopamine D2 receptor antagonists (e.g., metoclopramide)
• NK1 receptor antagonists exclusively
• Topical anticholinergics

Correct Answer: Dopamine D2 receptor antagonists (e.g., metoclopramide)

Q20. What is the preferred prophylactic approach for multiday moderately emetogenic chemotherapy?

• Single pre-treatment dose of 5-HT3 RA only on day 1
• Daily dosing of 5-HT3 RA plus dexamethasone on each day of chemotherapy; consider adding NK1 RA for high risk
• Only as-needed rescue antiemetics without scheduled prophylaxis
• Use cannabinoids alone throughout therapy

Correct Answer: Daily dosing of 5-HT3 RA plus dexamethasone on each day of chemotherapy; consider adding NK1 RA for high risk

Download