OCN Oncology Pharmacology 2 — Questions and Answers
Question 1: Which antifungal drug interaction is most important to monitor in patients receiving voriconazole and certain chemotherapy agents?
- CYP450 enzyme inhibition increasing chemotherapy drug levels (Correct answer)
- Reduced antiemetic efficacy
- Increased antibiotic resistance
- Decreased steroid effectiveness
Correct answer: CYP450 enzyme inhibition increasing chemotherapy drug levels
Voriconazole inhibits CYP450 enzymes and can dramatically increase plasma levels of chemotherapy drugs metabolized by the same pathway, causing toxicity.
Question 2: Aromatase inhibitors (e.g., anastrozole, letrozole) are used in postmenopausal breast cancer patients to achieve which effect?
- Block conversion of androgens to estrogen in peripheral tissues (Correct answer)
- Block estrogen at the receptor directly
- Suppress ovarian estrogen production
- Increase progesterone levels
Correct answer: Block conversion of androgens to estrogen in peripheral tissues
Aromatase inhibitors block the aromatase enzyme that converts androgens to estrogens in peripheral tissues, the main estrogen source in postmenopausal women.
Question 3: Tamoxifen requires conversion by CYP2D6 to its active metabolite endoxifen. What is the nursing implication?
- Avoid CYP2D6 inhibitors (e.g., fluoxetine) that reduce tamoxifen efficacy (Correct answer)
- Encourage high-fat diet to improve absorption
- Monitor for hypoglycemia regularly
- Administer only with antacids
Correct answer: Avoid CYP2D6 inhibitors (e.g., fluoxetine) that reduce tamoxifen efficacy
CYP2D6 inhibitors like fluoxetine block conversion of tamoxifen to its active metabolite, potentially reducing therapeutic efficacy in ER+ breast cancer.
Question 4: Colony-stimulating factors (e.g., filgrastim/G-CSF) are used in oncology patients primarily for which purpose?
- To stimulate neutrophil production and reduce febrile neutropenia risk (Correct answer)
- To prevent anemia from chemotherapy
- To increase platelet counts
- To reduce nausea from radiation
Correct answer: To stimulate neutrophil production and reduce febrile neutropenia risk
G-CSF agents like filgrastim stimulate the bone marrow to produce neutrophils, reducing the depth and duration of chemotherapy-induced neutropenia.
Question 5: Bisphosphonates such as zoledronic acid are used in oncology to treat which complications?
- Bone metastases, hypercalcemia of malignancy, and osteoporosis prevention (Correct answer)
- Brain metastases
- Liver metastases
- Lymphedema
Correct answer: Bone metastases, hypercalcemia of malignancy, and osteoporosis prevention
Zoledronic acid inhibits osteoclast activity to reduce skeletal-related events from bone metastases and treat hypercalcemia of malignancy.
Question 6: Which corticosteroid is most commonly used as part of antiemetic regimens for highly emetogenic chemotherapy?
- Dexamethasone (Correct answer)
- Prednisone
- Hydrocortisone
- Methylprednisolone
Correct answer: Dexamethasone
Dexamethasone is the preferred corticosteroid in CINV regimens due to its potency, long half-life, and synergistic antiemetic effect with 5-HT3 antagonists.
OCN Oncology Pharmacology 2
Which antifungal drug interaction is most important to monitor in patients receiving voriconazole and certain chemotherapy agents?