AOCNP Cancer Pharmacology and Chemotherapy 4 — Questions and Answers
Question 1: A patient on capecitabine develops palmar-plantar erythrodysesthesia (hand-foot syndrome). Which management strategy is most appropriate?
- Discontinue capecitabine permanently
- Dose reduce capecitabine and initiate pyridoxine and urea-based cream (Correct answer)
- Switch to IV 5-fluorouracil immediately
- Continue capecitabine without change and monitor weekly
Correct answer: Dose reduce capecitabine and initiate pyridoxine and urea-based cream
Grade 2-3 hand-foot syndrome requires capecitabine dose reduction, with supportive care including pyridoxine and emollient creams.
Question 2: Which of the following best describes the mechanism of action of bortezomib in multiple myeloma?
- Inhibits BCR-ABL tyrosine kinase
- Inhibits the 26S proteasome, preventing degradation of pro-apoptotic factors (Correct answer)
- Blocks PD-1/PD-L1 interaction to restore T-cell function
- Alkylates DNA leading to cross-linking and strand breaks
Correct answer: Inhibits the 26S proteasome, preventing degradation of pro-apoptotic factors
Bortezomib is a proteasome inhibitor that prevents degradation of regulatory proteins, promoting apoptosis in myeloma cells.
Question 3: A patient receiving high-dose methotrexate develops delayed clearance with rising creatinine. Which intervention is most critical?
- Administer leucovorin rescue and aggressive IV hydration with urinary alkalinization (Correct answer)
- Immediately start dialysis to remove methotrexate
- Give folic acid supplementation and observe
- Reduce methotrexate dose for the next cycle
Correct answer: Administer leucovorin rescue and aggressive IV hydration with urinary alkalinization
Leucovorin rescue combined with aggressive IV hydration and urinary alkalinization is essential to prevent life-threatening toxicity from delayed methotrexate clearance.
Question 4: Which toxicity is most specifically associated with bleomycin and requires monitoring with pulmonary function tests?
- Cardiotoxicity with reduced ejection fraction
- Pulmonary fibrosis and pneumonitis (Correct answer)
- Nephrotoxicity with rising creatinine
- Hepatotoxicity with elevated transaminases
Correct answer: Pulmonary fibrosis and pneumonitis
Bleomycin causes pulmonary toxicity ranging from pneumonitis to fibrosis, which can be life-threatening and requires baseline and serial PFTs.
Question 5: An AOCNP is managing a patient on tamoxifen who is also prescribed paroxetine for depression. What is the primary concern?
- Paroxetine increases tamoxifen levels causing toxicity
- Paroxetine inhibits CYP2D6, reducing conversion of tamoxifen to its active metabolite endoxifen (Correct answer)
- Paroxetine accelerates tamoxifen metabolism leading to subtherapeutic levels
- There is no clinically significant interaction between these agents
Correct answer: Paroxetine inhibits CYP2D6, reducing conversion of tamoxifen to its active metabolite endoxifen
Paroxetine is a potent CYP2D6 inhibitor that significantly reduces conversion of tamoxifen to endoxifen, potentially reducing efficacy of hormonal therapy.
Question 6: Which VEGF pathway inhibitor is associated with a unique toxicity profile including hand-foot skin reaction, hypertension, and hepatotoxicity, and requires liver function monitoring?
- Bevacizumab
- Sorafenib (Correct answer)
- Ramucirumab
- Ziv-aflibercept
Correct answer: Sorafenib
Sorafenib, a multi-kinase inhibitor targeting VEGFR and RAF, is specifically associated with hand-foot skin reaction, hypertension, and hepatotoxicity requiring LFT monitoring.
Question 7: A patient with colorectal cancer is found to have a RAS mutation. Which targeted therapy should be avoided?
- Bevacizumab
- Cetuximab (Correct answer)
- Ramucirumab
- Ziv-aflibercept
Correct answer: Cetuximab
RAS mutations (KRAS or NRAS) confer resistance to EGFR inhibitors such as cetuximab and panitumumab, making these agents ineffective.
AOCNP Cancer Pharmacology and Chemotherapy 4
A patient on capecitabine develops palmar-plantar erythrodysesthesia (hand-foot syndrome).
Which management strategy is most appropriate?