2.8 Cytotoxic drugs Flashcards
what cell cycle phase does DNA synthesis occur in?
G2
cell cycle specific or non-specific?
- tumour specific
- duration of dose more important than dose
cell cycle specific
what is the class and action of methotrexate?
inhibits dihydrofolate reductase
anti-metabolite - impairs nucleotide synthesis/incorportation
cell cycle specific
what is the class and action of 6MP/cytosine arabinoside and fludarapine?
these get incorportated into DNA
- antimetabolite
what is the class and action of hydroxyurea?
impaired deoxynucleotide synthesis (ribonucleotide reductase)
what drug inhibits the unwinding of DNA?
cell cycle specific or non-specific?
topoisomerase II
non cell cycle specific
what are 2 examples of mitotic spindle inhibitors?
vinca alkaloids- vicristine, vinblastine
taxotere - taxol
these are plant derived and are cell cycle specific
what is the downfall of non-cell specific chemotherapies?
What is more important- cumulative dose or max dose?
they damage normal stem cells
cumulative dose is more important than duration (they don’t have to wait around for the right cell cycle to work)
How do chlorambucil and melphalan work?
alkylating agents that bind covalently to DNA (form adducts)
produces DNA strand breaks by free radical production
cis-platin and carboplatin
cell cycle specific or non-cell cycle specific?
non-cell cycle specific
so total dose more important than duration of dosing
how do the cytotoxic antibiotics work?
- daunorubicin
- doxorubicin
- idarubicin
reversible DNA intercalation
impaires RNA transcription
strands breaks in DNA ( free radicals)
immediate side effects of cytotoxics
bone marrow suppression
gut mucosal damage
hair loss
drug specific side effect of vinca alkaloids?
neuropathy- nerves
drug specific side effect of anthracyclines?
cardiotoxicity
cardiomyopathy
drug specific side effet of cis-platinum?
nephrotoxicity- kidney
