Cytotoxic Drugs Flashcards
What are the different parts of the cell cycle?
G0 to G1
G1 to S
S to G2 (DNA synthesis)
G2 to M
What are the general characteristics of cell cycle specific chemo agents?
Tumour specific
Duration of exposure more important than dose
What are examples of cell cycle specific chemo agents?
Antimetabolites; impairs nucleotide synthesis/ incorporation
Mitotic spindle inhibitors
What are examples of antimetabolites?
Methotrexate: Inhibits dihydrofolate reductase 6-Mercaptopurine/ cytosine arabinoside: Incorporated into DNA Hydroxyurea: Impaired deoxynucleotide synthesis
What are examples of mitotic spindle inhibitors?
Vinca alkaloids; vincristine/ vinblastine
Taxotere (taxol)
What are the general characteristics of non-cell cycle specific agents?
Non-tumour specific; damage normal stem cells
Cumulative dose more important than duration
What are examples of non-cell specific agents?
Alkylating agents
Platinum derivatives
Cytotoxic antibiotics
What are examples of alkylating agents?
Chlorambucil/ melphalan
Bind covalently to bases of DNA and produce DNA strand breaks by free radical production
What are examples of platinum derivatives?
Cisplatin
Carboplatin
What are examples of cytotoxic antibiotics?
Anthracyclines; daunorubicin/ doxorubicin/ idarubicin
DNA intercalculation, impair RNA transcription, form free radicals via strand breaks in DNA
What are the immediate side effects to cytotoxic drugs?
Bone marrow suppression
Gut mucosal damage
Alopecia
What are examples of drug specific side effects?
Vinca alkaloids; neuropathy
Anthracyclines; cardiotoxicity
Cisplatin; nephrotoxicity
What are some specific side effects to alkylating agents?
Infertility
Secondary malignancy
What is the basis of combo chemo administration?
Non-cross resistant drug combos
Non-overlapping toxicity spectra
Additive/ synergistic mechanisms of action
Why will chemo fail?
Slow tumour doubling time
Drug resistant mechanisms