Pharmacology of Neoplasia

Question 1

Toxicity

Answer 1

common theme among all cancer drugs

Question 2

Alkylating agents

Answer 2

alter the shape of DNA by covalently bonding an “alkyl” group to the double helix within a cancer cell; prevent DNA from duplicating & kill cancer cells when they divide; subclasses (nitrogen mustards, nitrosureas, platinum compounds); primary dose-limiting effect = myelosuppression

Question 3

Antimetabolites

Answer 3

disrupt metabolic pathways of cancer cells; cell cycle specific; subclasses (folic acid analogs, purine analogs, pyrimidine analogs)

Question 4

Folic acid analogs

Answer 4

toxic to normal cells and cancer cells; needed to make new DNA

Question 5

leucovorin

Answer 5

used to “rescue” normal cells during folic acid analog therapy; able to enter normal cells but not cancer cells & is used to continue normal cell functioning

Question 6

Antitumor antibiotics

Answer 6

contain substances obtained from bacteria that have the ability to kill cancer cells; bind to DNA to produce effects; must be given IV; major dose-limiting toxicity is myelosuppression

Question 7

dexrazoxane (Zinecard)

Answer 7

used to “rescue” cardiac tissue during therapy with anti tumor antibiotics

Question 8

Selective estrogen receptor blockers (SERMS)

Answer 8

type of hormone antagonist; activate or inhibit estrogen receptors (activate in bone; inhibit in breast); only effective in hormone-sensitive tumors; NOT cytotoxic

Question 9

aromatase inhibitors

Answer 9

blocks synthesis of estrogen in the blood (but not estradiol formation in ovary); first-line treatment for postmenopausal women w/ER-positive breast cancer

Question 10

Gonadotropin-releasing hormone analogs

Answer 10

initially increases production of interstitial cell stimulating hormone; eventually insesitivity develops and starves prostate of testosterone

Question 11

Androgen receptor blockers

Answer 11

prevents testosterone and other androgens from reaching receptors in prostate

Question 12

Biologic response modifiers

Answer 12

act directly by binding to cancer cells and killing them or indirectly by activating the immune response

Question 13

Antiemetics

Answer 13

given to nearly all chemo pt’s to decrease/prevent n/v

Question 14

cyclophosphamide (Cytoxan)

Answer 14

antineoplastic agent; alkylating agent; nitrogen mustard
USE: various cancers
MOA: prodrug that binds to DNA & forms cross-links which prevent DNA synthesis
AE: alopecia, myelosuppression, severe infection, sepsis, secondary malignancies, cardio toxicity, etc
Contraindicated: pregnancy, lactation, & severe myelosuppression
Pregnancy Category D

Question 15

methotrexate (MTX)

Answer 15

antineoplastic agent; antimetabolite; folic acid analog
USE: various cancers, combination therapy to maintain remissions
MOA: blocks enzyme responsible for converting folic acid into folate; cell cycle specific
AE: myelosuppression, hepatotoxicity, ulcerative stomatitis, diarrhea, infection, pulmonary toxicity, skin reactions; crosses BBB
Pregnancy Category X

Question 16

doxorubicin (Adriamycin)

Answer 16

antineoplastic; antitumor antibiotic
USE: solid tumors in various cancers
MOA: binds to DNA to decrease synthesis; cell-cycle nonspecific
AE: Myleosuppression and cardiotoxicty (RED DEATH); can turn tears or urine red (harmless); complete loss of hair, anaphylaxis, extravasation, secondary malignancies, n/v, mucositis, rash, excessive lacrimation, hepatotoxicity, & radiation recall phenomenon
Pregnancy: use contraception

Question 17

vincristine (Oncovin)

Answer 17

antineoplastic; vinca alkaloid; mitotic inhibitor
USE: various cancers
MOA: binds to tubulin proteins necessary for cell division = cell death; cell cycle specific - mitosis
AE: neurotoxicity, CNS effects, myelosuppression
BLACK BOX WARNING: extravasation
Pregnancy Category D

Question 18

tamoxifen (Nolvadex)

Answer 18

antineoplastic, hormonal agent, estrogen receptor blocker
USE: ER-positive breast cancer
MOA: binds to ERs, causing agonist effects in bone & antagonist effects in the breast
AE: increased risk of endometrial cancer
BLACK BOX WARNING: thromboembolic events
Contraindicated: anticoagulant therapy, preexisting endometrial hyperplasia, hx thromboembolic events, pregnancy, & lactation
Pregnancy Category D