Cytotoxic drugs Flashcards Preview

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Flashcards in Cytotoxic drugs Deck (15)
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1
Q

What are the general characteristics of cell cycle specific agents?

A

Tumour specific Duration of exposure more important than dose

2
Q

What are the different types of cell cycle specific agents?

A

Antimetabolites - impair nucleotide synthesis/incorporation Mitotic spindle inhibitors

3
Q

What are some examples of antimetabolites?

A

Methotrexate - inhibits dihydrofolate reductase 6-mercaptopurine/cytosine arabinoside/fludarabine - incorporated into DNA Hydroxyurea - impaired deoxynucleotide synthesis

4
Q

What are some examples of mitotic spindle inhibitors?

A

Plant derivatives; vinca alkaloids (vincristine/vinblastine), taxotere (Taxol)

5
Q

What are the general characteristics of non-cell cycle specific agents?

A

Non-tumour specific; damage normal stem cells Cumulative dose more important than duration

6
Q

What are the different types of non-cell cycle specific agents?

A

Alkylating agents Platinum derivatives Cytotoxic antibiotics

7
Q

What are some examples of alkylating agents and how do they work?

A

Chlorambucil/melphalan Bind covalently to bases of DNA Produces DNA strand breaks (mutation) by free radical production

8
Q

What are some examples of platinum derivatives?

A

Cis-platinum/carboplatin

9
Q

What are some examples of cytotoxic antibiotics and how do they work?

A

Anthracyclines - daunorubicin/doxorubicin/ idarubicin DNA intercalation Impairs RNA transcription Strand breaks in DNA

10
Q

What are some of the potential immediate side effects of cytotoxic drugs?

A

Affects rapidly dividing organs - bone marrow suppression, gut mucosal damage, hair loss

11
Q

What are some examples of drug specific side effects?

A

Vinca alkaloids - neuropathy Anthracyclines - cardiotoxicity Cis-platinum - nephrotoxicity

12
Q

What are some examples of drug specific long term side effects?

A

Alkylating agents - infertility, secondary malignancy Anthracyclines - cardiomyopathy

13
Q

Why does chemotherapy sometimes fail?

A

Slow tumour doubling time Tumour sanctuaries Drug resistance mechanisms e.g. increased DNA repair in cis-platinum resistance

14
Q

Why is intensifying chemotherapy limited and how can this be overcome?

A

Limited by myelosuppression Overcome by use of haematopoietic growth factors, combine myelosuppressive with non-myelosuppressive agents and intensify dose of active drugs + stem cell rescue

15
Q

What are the potential sources of stem cells for transplantation?

A

Tissue source - blood versus bone marrow Patient source; autologous or allogenic (sibling, unrelated)