Chemotherapy Flashcards
what are the 4 classes of chemotherapy agents
antimetabolites
alkylating agents
intercalating agents
spindle poisons
how do antimetabolites work
they prevent DNA synthesis
how do alkylating agents work
they prevent DNA replication by creating bonds between the 2 strands so that they cant be unwound to allow replication
how do intercalating agents work
they prevent DNA replication by inserting bulky adducts into the strands
what are the 2 types of spindle poisons
taxoids and vinca alkaloids
how do taxoids work
they allows spindle assembly but prevent the disassembly of them so the chromosomes aren’t released
how do vinca alkaloids work
they prevent the spindle fibres from forming
how are doses of chemotherapy agents given
in fractionated doses
why are chemotherapy agents given in fractionated doses
as limits the amount of damage to healthy cells as they recover quicker than the tumour cells
what must you take into account when deciding the dosage of a chemotherapy agent
patient BMI
drug handling ability (liver.kidney problems)
general wellbeing
list some of the side effects of chemotherapy
renal failure vomiting alopecia DIC mucositis lung toxicity
what can be done to help with alopecia
scalp cooling
what mechanisms of chemotherapy drug resistance are there
DNA repair mechanisms - these repair the DNA strand breaks cause by intercalating agents
decreased entry - proteins on cell surface prevent drug entry
inactivation of agents - proteins inside the cancer cell bind to drug to render it inactive
how does chemotherapy and cancer affect the pharmacokinetics and dynamics of the chemotherapy agents
absorption - nausea and vomiting reduce absorption
distribution - weight loss reduces distribution. ascites from cancer means drug may sit in fluid.
elimination - if cancer affects the liver
what drugs can interact with chemotherapy agents to increase their effect
antifungals
warfarin
St John Wort
grapefruit juice
