Hem & Onc - Pharm (Groups of Cancer Drugs) Flashcards

Pg. 401-405 in First Aid 2014 or Pg. 369-375 in First Aid 2013 Sections include: -Cancer drugs-cell cycle -Antineoplastics -Antimetabolites -Antitumor antibiotics -Alkylating agents -Microtubule inhibitors

1
Q

What are the phases of the cell cycle and the major event occurring in each? Which cancer drugs act at each phase?

A

G1 - Synthesis of components needed for DNA synthesis = NO DRUGS ACT HERE; S - DNA Synthesis = ANTIMETABOLITES & ETOPOSIDE act here; G2 - Synthesis of components needed for mitosis = ETOPOSIDE & BLEOMYCIN act here; M - Mitosis = VINCA ALKALOIDS & TAXOLS act here (Note: G0 [rest] & Differentiation exit out of the cycle)

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2
Q

Which drug acts at multiple phases in the cell cycle? What are the phases in which it acts?

A

Etoposide; S & G2

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3
Q

What are the steps leading up to neoplastic cell division, starting at nucleotide synthesis and ending with cellular division? What are the important drugs that act at each step?

A

(1) Nucleotide synthesis - METHOTREXATE/5-FU & 6-MP (2) DNA - ALKYLATING AGENTS/CISPLATIN, DACTINOMYCIN/DOXORUBICIN, & ETOPOSIDE (3) RNA - NONE (4) Protein - NONE (5) Cellular Division - VINCA ALKALOIDS & PACLITAXEL

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4
Q

On what general process do methotrexate and 5-FU act? More specifically, what is their effect?

A

Nucleotide synthesis; Decrease thymidine synthesis

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5
Q

On what general process does 6-MP act? More specifically, what is its effect?

A

Nucleotide synthesis; Decrease purine synthesis

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6
Q

On what general process do Alkylating agents & Cisplatin act? More specifically, what is their effect?

A

DNA (Synthesis); Cross-link DNA

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7
Q

On what general process do Dactinomycin and Doxorubicin act? More specifically, what is their effect?

A

DNA (Synthesis); DNA intercalators

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8
Q

On what general process does Etoposide act? More specifically, what is its effect?

A

DNA (Synthesis); Inhibits topoisomerase II

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9
Q

On what general process do Vinca alkaloids act? More specifically, what is their effect?

A

Cellular division; Inhibit microtubule formation

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10
Q

On what general process does Paclitaxel act? More specifically, what is its effect?

A

Cellular division; Inhibits microtubule disassembly

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11
Q

What are 4 examples of antimetabolites? In what phase of the cell cycle do all of these cancer drugs act?

A

(1) Methotrexate (MTX) (2) 5-fluorouracil (5-FU) (3) Cytarabine (arabinofuranosyl cytidine) (4) Azathioprine/6-mercaptopurine (6-MP)/6-thioguanine (6-TG); S-phase

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12
Q

What is MTX? What is its mechanism?

A

Methotrexate; Folic acid analog that inhibits dihydrofolate reductase –> decreased dTMP –> decreased DNA and decreased Protein synthesis

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13
Q

What are the 4 cancers for which methotrexate is clinically used? What 5 other non-neoplastic clinical uses does methotrexate have?

A

CANCERS: (1) Leukemias (2) Lymphomas (3) Choriocarcinoma (4) Sarcomas; NON-NEOPLASTIC: (1) Abortion (2) Ectopic pregnancy (3) Rheumatoid arthritis (4) Psoriasis (5) IBD

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14
Q

What are the 4 toxicities/side effects associated with methotrexate?

A

(1) Myelosuppression (which is rversible with leucovorin [folinic acid] “rescue”) (2) Macrovesicular fatty change in liver (3) Mucositis (4) Teratogenic

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15
Q

What is 5-FU? What is its mechanism?

A

5-fluorouracil; Pyrimidine analog bioactivated to 5F-dUMP, which covalently complexes folic acid. This complex inhibits thymidylate synthase –> Decreased dTMP –> Decreased DNA & Decreased protein synthesis

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16
Q

What are the 3 cancers for which 5-FU is clinically used?

A

(1) Colon cancer (2) Pancreatic cancer (3) Basal cell carcinoma (topical)

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17
Q

What are the 2 toxicities/side effects associated with 5-FU?

A

(1) Myelosuppression (which is not reversible with leucovorin; instead, overdose rescue with uridine) (2) Photosensitivity

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18
Q

What is the major toxicity/side effect shared by both MTX and 5-FU? How is it handled in each case?

A

MYELOSUPPRESION; w/ MTX - reversible with leucovorin (folinic acid) “rescue… w/ 5-FU - not reversible with leucovorin, but instead overdose rescue with uridine

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19
Q

What is another name for Cytarabine? What is its mechanism?

A

Arabinofuranosyl cytidine; Pyrimidine anlog –> inhibition of DNA polymerase

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20
Q

What are the 2 cancers for which Cytarabine is clinically used?

A

(1) Leukemias (2) Lymphomas

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21
Q

What are the 3 toxicities/side effects associated with Cytarabine?

A

(1) Leukopenia (2) Thrombocytopenia (3) Megaloblastic anemia; Think: “CYTarabine causes panCYTopenia.”

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22
Q

What other drugs share the same mechanism as Azathioprine? What is this mechanism? What activates them to take this action?

A

6-Mercatopurine (6-MP) & 6-Thioguanine (6-TG); Purine (thiol) analogis –> Decrease de novo purine synthesis; HGPRT

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23
Q

What 3 conditions are prevented with use of Azathioprine?

A

Preventing organ rejection, RA, SLE (azathioprine)

24
Q

Where are the 3 toxicities/side effects associated with Azathioprine, 6-MP, and 6-TG?

A

(1) Bone marrow (2) GI (3) Liver

25
Q

Which drugs are metabolized by xanthine oxidase? Given this fact, what increases toxicity of this drug, and why?

A

Azathioprine and 6-MP are metabolized by xanthine oxidase; thus both have increased toxicity with allopurinol, which inhibits their metabolism

26
Q

What are the antitumor antibiotics?

A

(1) Dactinomycin (actinomycin D) (2) Doxorubicin (Adriamycin, daunorubicin) (3) Bleomycin

27
Q

What is the brand name for Dactinomycin? What is its mechanism?

A

Actinomycin D; Intercalates in DNA

28
Q

For what 3 cancers is dactinomycin used clinically? In general, how is dactinomycin used clinically?

A

(1) Wilms’ tumor (2) Erwing’s sarcoma (3) Rhadomyosarcoma; Used for children tumors (Think: “children ACT out”)

29
Q

What is/are the toxcity(-ies) associated with Dactinomycin?

A

Myelosuppression

30
Q

What is the brand name for Doxorubicin? What is another drug that shares the same mechanism? What is their mechanism?

A

Adriamycin; Daunorubicin; Generate free radicals. Noncovalently intercate in DNA –> breaks in DNA –> Decreased replication

31
Q

For what 3 cancers are doxorubicin/daunorubicin used clinically?

A

(1) Solid tumors (2) Leukemias (3) Lymphomas

32
Q

What is/are the toxcity(-ies) associated with Doxorubicin/daunorubicin?

A

(1) Cardiotoxicity (dilated cardiomyopathy) (2) Myelosuppression (3) Alopecia (4) Toxic to tissues following extravasation

33
Q

What is used to prevent cardiotoxicity as a result of doxorubicin/daunorubicin, and what kind of agent is this?

A

Dexrazoxane (iron chelating agent), used to prevent cardiotoxicity

34
Q

What is the mechanism of bleomycin?

A

Induces free radical formation, which causes breaks in DNA strands

35
Q

For what 2 cancers is bleomycin clinically used?

A

(1) Testicular cancer (2) Hodgkin’s lymphoma

36
Q

What are 4 toxicities associated with Bleomycin? Which of these is minimal (relative to other antitumor drugs)?

A

(1) Pulmonary fibrosis (2) Skin changes (3) Mucositis. (4) Minimal myelosuppression

37
Q

What are 3 examples of alkylating agents?

A

(1) Cyclophosphamide, ifosfamide (2) Nitrosoureas (carmustine, lomustine, semustine, streptozocin) (3) Busulfan

38
Q

What other drug shares the same mechanism as cyclophosphamide? What is their mechanism? What is required for this action to occur?

A

Ifosfamide; Covalently X-link (interstrand) DNA at guanine N-7; Require bioactivation by liver

39
Q

For what 4 cancers are cyclophosphamide and/or ifosfamide clinically used?

A

(1) Solid tumors (2) Leukemia (3) Lymphomas (4) Some brain cancers

40
Q

What are 2 toxicities associated with cyclophosphamide and/or ifosfamide?

A

(1) Myelosuppression (2) Hemorrhagic cystitis (partially prevented with mesna [thiol group of mesna binds toxic metabolite])

41
Q

What prevents hemorrhagic cystitis from cyclophosphamide/ifosfamide usage, and how?

A

Hemorrhagic cystitis, partially prevented with mesna (thiol group of mesna binds toxic metabolites)

42
Q

What are 4 examples of Nitrosoureas? What is their mechanism? What is required for this action?

A

(1) Carmustine (2) Lomustine (3) Semustine (4) Streptozocin; Cross blood-brain barrier –> CNS; Cross-links DNA; Require bioactivation

43
Q

For what cancers are Nitrosoureas used clinically?

A

Brain tumors (including glioblastoma multiforme)

44
Q

What kind of toxicity and/or side effects are associated with Nitrosoureas?

A

CNS toxicity (convulsions, dizziness, ataxia)

45
Q

What is the mechanism of Busulfan?

A

Cross-links DNA

46
Q

What are 2 clinical uses for Busulfan?

A

(1) CML (2) Ablate patient’s bone marrow before bone marrow transplantation

47
Q

What are 3 toxicities associated with Busulfan? Which of these occurs in almost all cases?

A

(1) Severe myelosuppression (in almost all cases) (2) Pulmonary fibrosis (3) Hypersegmentation

48
Q

What are 2 examples of microtubule inhibitors?

A

(1) Vincristine, vinblastine (2) Paclitaxel, other taxols

49
Q

What drug shares the same mechanism as vincristine? What is their mechanism and ultimate effect?

A

Vinblastine; Vinca alkaloids that bind to Beta-tubulin, inhibit its polymerization into microtubules, thereby preventing mitotic spindle formation (M-phase arrest)

50
Q

For what 3 cancers are vincristine and/or vinblastine used clinically?

A

(1) Solid tumors (2) Leukemias (3) Lymphomas

51
Q

What toxicities are associated with vincristine versus vinblastine?

A

VINCRISTINE - Neurotoxicity (areflexia, peripheral neuritis), paralytic ileus; VINBLASTINE - BLAsts bone marrow (suppression)

52
Q

What is the mechanism and ultimate effect of Paclitaxel and other Taxols?

A

Hyperstabilize polymerized microtubules in M phase so that mitotic spindle cannot break down (i.e., anaphase cannot occur); Think: “it is TAXing to stay polymerized”

53
Q

For what 2 cancers are Paclitaxel and/or other Taxols clinically used?

A

(1) Ovarian (2) Breast carcinomas

54
Q

What 3 toxicities are associated with Paclitaxel and/or other Taxols?

A

(1) Myelosuppression (2) Alopecia (3) Hypersensitivity

55
Q

What are 2 conditions treated by 6-MP? What other drug is used to treat these same conditions?

A

Leukemia, IBD (6-MP, 6-TG)

56
Q

Draw a diagram showing the relationship between the following: (1) CH2-THF (2) DHF (3) DHF reductase (4) dTMP (5) dUMP (6) F-FU (7) MTX (8) THF (9) Thymidylate synthase.

A

See p. 403 in First Aid 2014 for diagram at bottom of page