Chemotherapy Flashcards
What is the mechanism of action of vinca alkaloids?
Vinca alkaloids bind to the microtubule apparatus/spindles in the cell and inhibit mitosis by disrupting microtubule function.
What is the mechanism of action of alkylating agents?
Alkylating agents bind covalently to DNA/RNA molecules and introduce an alkyl group to specific sites. This causes cross-linking between strands of DNA, interfering with the normal separation of strands and preventing mitosis. The long-term effects are therefore mutation and cell death. The alkylating agents are the most toxic on cells in the division phase of the cell cycle. The platinates work in a similar way by adding a form of platinum instead of an alkyl group to DNA/RNA.
What is the mechanism of action of cytotoxic antibiotics?
Cytotoxic antibiotics insert themselves in between DNA base pairs, inhibiting the enzyme topoisomerase-II during DNA replication and transcription and blocking DNA/RNA synthesis. This causes irreparable breaks in DNA.
What is neutropenia and why is it hazardous to patients? During chemotherapy, when does the neutrophil count fall to its lowest levels, and how long after chemotherapy do they recover?
Neutropenia is a condition characterised by abnormally low levels of neutrophils. For the majority of chemotherapy regimens, the neutrophil count falls to its lowest levels approximately 5 -7 days after the administration of chemotherapy and it can take up to 2 - 4 weeks to recover. There is a tendency for neutropenic sepsis to occur more commonly in the first two cycles of treatment. Neutropenia predisposes patients to the risk of infection.
What is thrombocytopenia and why is it hazardous to patients? During chemotherapy, when does the platelet count fall to its lowest levels, and how long after chemotherapy do they recover?
Thrombocytopenia is a condition characterised by abnormally low levels of platelets. For many types of chemotherapy, the platelet count falls and reaches its lowest levels approximately 7 – 14 days after the administration of chemotherapy and can take 4 – 5 weeks
to recover. Thrombocytopenia predisposes patients to the risk of bleeding.
