Chemotherapy Agents Flashcards
What are alkylating agents and platins and how do they work
They cross link DNA strands which cause breaks in the strand which cannot be repaired, often by cross linking between two separate strands or by two points on the same strand.
What are the three platins used?
- Cisplatin
- Carboplatin
- Oxaliplatin
How do Platins work?
Interacts with the nucleotide bases in cancer cell DNA, the N atoms in the nucleotide bases form strong N-Pt link with the loss of the leaving group
How do Antimetabolites work?
They interfere with nucleoside (cytosine, uracil) inclusion in RNA or DNA
They also inhibit enzymes involved in DNA synthesis.
Antimetabolites are purine or pyrimidine analogues, apart from methotrexate which is a folate antagonist
How to vinca alkaloids work?
They block the formation of the mitotic spindle, stopping assembly of tubulin dimers and cell division.
What examples are their of vinca alkaloids?
Vincristine, for mylomas, lymphomas, solid tumours.
How do topoisomerase inhibitors work?
They prevent the supercoiling of DNA required for the DNA to fit in the available space by inhibiting the enzyme topoisomerase.
What are examples of topoisomerase I inhibitors
Irinotecan and topotecan.
What are examples of topoisomerase II inhibitors
Etoposide, causes irreversible double strand breaks in DNA
What are the two ways anthracyclines (antitumour antibiotics) work?
Intercalation, where the drug inserts itself between base pairs of the DNA preventing replication or production of mRNa
Also bind to DNA causing single and double strand breaks to form free radicals
Examples of anthracyclines?
Daunorubicin, flat so slide newtly inbetween DNA strands, stopping replication
What are the three other types of chemotherapy treatments?
- Asparaginase - depletes asparagine
- Interferons - cytokine immunomldulators
- Hormones:
Glucocorticoids
Tamoxifen
GnRH analogues
Aromatase Inhibitors
What are the two main adjunctive agents used?
1 Folinic Acid
2 MESNA
How does Folinic Acid work with Fluorouracil?
Given in combination with fluorouracil, where it enhances fluorouracil to an enzyme in cancer cells, so it stays in cancer cells for longer
Has no serious side effects but can worsen side effects of fluorouracil.
How does Folinic Acid work with methotrexate
Methotrexate works by competing and and counteracting with folic acid in cancer cells, which results in folic acid deficiency, but this also occurs in normal cells, causing side effects, these side effects are lessened with folinic acid as it provides an active form of folic acid for the bodies cells.
