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Flashcards in Anti cancer drugs Deck (53)
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1

Target unique structure (or expressed element) or process associated with cancerous cell

Selective toxicity

2

What is the mechanism of alkylating agents?

Insert alkyl group into DNA structure; cross-link between adjacent bases, particularly guanine bases, as well as proteins; cause stress in molecules leading to strand breaks and apoptosis

3

Which stage of the cell cycle do alkylating agents target?

generally, cycle non-specific

4

What does a bifunctional alkylating agent do?

Causes intrastrand linking and cross-linking

5

Why are cytotoxic antibiotics used in cancer therapy?

Too toxic to use in infectious disease therapy; the cost vs benefit ratio is different in cancer

6

What is the mechanism of cytotoxic antibiotics?

Inhibit transcription and translation processes

7

What do antimetabolites do?

Substitute themselves in the DNA synthesis pathway, block DNA synthesis, make molecule non-functional

8

Which stage of the cell cycle to antimetabolites target?

S phase

9

What are the three pathways by which antimetabolites may block DNA synthesis?

Folate pathway, pyrimidine base synthesis, purine base synthesis

10

Which pathway does methotrexate target?

Folate pathway, similar shape to folic acid

11

What is the mechanism of mitotic poisons?

Inhibit microtubule function so that mitotic spindles don't form or inhibit topoisomerase

12

Which stage of the cell cycle to mitotic poisons target?

M phase

13

Examples of mitotic poisons?

vinca alkaloids (from periwinkle plant), taxanes (European yew tree), etiposide (mandrake)

14

What is the mechanism of SERM?

Selective oestrogen receptor modulator agonises some oestrogen receptors (for bone development and blood coagulation) and antagonises others (in breast tissue)

15

What is the mechanism of aromatase inhibitors?

Lower circulating oestrogen (aromatase is used by fat cells to convert precursor substances into oestrogen)

16

2 drug groups used to treat breast cancer?

SERM and aromatase inhibitors

17

2 drug groups used to treat prostate cancer?

antiandrogens and gonadotrophin-RH analogues

18

Mechanism of antiandrogens?

Prevent access to growth factor, stops growth of cancer

19

Mechanism of gonadotrophin-RH analogues

Gonadotrophin releasing hormone, released from hypothalamus to act on pituitary gland to stimulate LH and FSH; analogue is given repeatedly to change HP axis and cause a decrease in LH secretion

20

Drug group used to treat blood-borne cancers e.g. leukaemia, lymphoma

Glucocorticoids

21

Mechanism of action of glucocorticoids

High doses lead to lysis of affected cells

22

Common adverse effects of glucocorticoids

Also target rapidly dividing normal cell populations:
alopecia (hair follicles)
skin blistering and necrosis
gastrointestinal sores (stomatitis) and mouth inflammation (mucositis)
nausea and vomiting
infertility (for duration of therapy)
bone marrow suppression (bone marrow cells have rapid turnover)
organ toxicity - may occur after therapy is finished

23

Examples of organ toxicity from glucocorticoids

heart: dysrhythmia and altered contractility, acute heart failure
Kidneys: renal failure
nervous system: paraesthesias (numbness, tingling, burning sensation as a result of altered axonal transport) microtubules affecting cell division and axonal transport
urinary bladder: haemorrhagic cystitis

24

What are 2 drug groups that address the adverse drug reactions (ADR) of glucocorticoids?

Antiemetic drugs
Colony stimulating factors

25

Examples of antiemetic drugs

- dopamine/serotonin/neurokinin receptor antagonists e.g. dopamine connecting medulla to vomiting centre
- metoclopramide (maxolon) = dopamine receptor antagonist, ondansetron = serotonin receptor antagonist, aprepitant (Emend) = substance P receptor antagonist
- glucocorticoids (dexamethasone)

26

Examples of CSFs

Colony stimulating factors
- filigrastim
- erythropoietin

27

Mechanism for CSFs

stimulate white blood cell populations

28

What compound can be used to manage organ toxicity?

Mesna for alkylating agents (cyclophosphamide and ifosfamide)

29

Mechanism of Mesna?

Prevents formation of metabolite that causes hemorrhagic cystitis without affecting the metabolite that's causing the desired action

30

Describe monoclonal antibody production

Mouse immunised, antibody-forming cells taken out of spleen, tumour cells are grown in tissue culture, antibody-forming cells are fused with the tumour cells, antibody-producing 'hybridomas' are cloned