Cytotoxic drugs Flashcards
(17 cards)
Classification of cytotoxic drug classification?
Cell cycle specific
Non cell cycle specific
Features of cell cycle specific agents?
Tumour specific
Duration of exposure more important than dose
Types of cell cycle specific agents?
Antimetabolites (impair nucleotide synth)
Mitotic spindle inhibitors
Antimetabolites?
Methotrexate (Dihydrofolate reductase inhibitor)
6-Mercaptopurine (incorporated into DNA)
Hydroxyurea (Impaired deoxynucleotide synthesis)
Method of action of dihydrofolate reductase inhibitors?
Dihydrofolate reductase needed to metabolise folate into thymine needed for cell division
Mitotic spindle inhibitors?
Vincristine/Vinblastine
Taxotere
Features of non cell cycle specific agents?
Non tumour specific; damage normal stem cells
Cumulative dose more important than duration
Types of non cell specific agents?
Alkylating (Chlorambucil, melphalan)
Platinum derivs (Cis-platinum)
Cytotoxic Abx (Anthracyclines eg Daunorubicin)
How do alkylating agents work?
Bind covalently to DNA bases
Produces DNA strand breaks by free radical production
How do cytotoxic antibiotics work?
Impair RNA transcription
Strand breaks in DNA
Cytotoxic drugs general side effets (immediate)?
Bone marrow suppression
Gut mucosal damage
Hair loss
Specific SE of vinca alkaloids?
Neuropathy
Specific side effects of anthracylines?
Cardiotoxic
Specific SE of cis platinum?
Nephrotoxicity
Long term side effects of cytotoxic drugs?
Alkylating agents- Infertility
Secondary malignancy
Anthrayclines- Cardiomyopathy
Why does chemo fail?
Drug resistance mechanisms
Slow tumour doubling time
Tumour sanctuaries
How is chemotherapy intensified?
Use haemopoietic GF
Combine myelosuppressive agents with non-myelosuppressive
Intensify doses of active drugs
