Oncology Pharmacology Flashcards

Which antifungal drug interaction is most important to monitor in patients receiving voriconazole and certain chemotherapy agents?

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.

Aromatase inhibitors (e.g., anastrozole, letrozole) are used in postmenopausal breast cancer patients to achieve which effect?

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.

Tamoxifen requires conversion by CYP2D6 to its active metabolite endoxifen. What is the nursing implication?

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.

Colony-stimulating factors (e.g., filgrastim/G-CSF) are used in oncology patients primarily for which purpose?

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.

Bisphosphonates such as zoledronic acid are used in oncology to treat which complications?

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.

Which corticosteroid is most commonly used as part of antiemetic regimens for highly emetogenic chemotherapy?

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.