Anti-Neoplastic Drugs, Pt. 3 Flashcards
Where do most chemotherapeutic drugs exert their effect?
rapidly dividing cancer cells, but can also include normal cells that divide rapidly, like cells that line the GI tract, hair cells, and blood cells
What are the 6 major categories of chemotherapeutic drugs?
- alkylating agents
- antimetabolites
- plant alkaloids (mitotic inhibitors)
- cytotoxic antibiotics
- topoisomerase inhibitors
- corticosteroids
What are the 3 classes of chemotherapeutic drugs?
- cell cycle specific (CCS) - antimetabolites (S), vinca alkaloids and taxanes (M), topoisomerase inhibitors (G1-S, G2-M), anti-tumor antibiotics (G2-M)
- cell cycle non-specific (CCNS) - alkylating agents, platinum analogs, antibiotics (anthracyclines)
- miscellaneous anticancer agents
Cell cycle specific (CCS) chemotherapeutic drugs:
What is the mechanism of action of antimetabolites? Where in the cell cycle do they act?
interfere with DNA and RNA biosynthesis by preventing de novo nucleotide production - insert themselves into nucleotides to cause DNA breakage and deletion
S phase
What are the 4 classes of antimetabolites?
(CCS)
1. antifolates - Methotrexate
2. pyrimidine analogs - 5-Fluorouracil
3. deoxycytidine analogs - Cytarabine, Gemcitabine
4. purine antagonists - 6-Mercaptopurine, 6-Thioguanine
What 3 cancers are treated with Methotrexate? What is another therapeutic use?
- lymphoma
- carcinoma
- sarcoma
(in dogs and cats)
immunosuppressive
What antimetabolite is not commonly included in combination therapy? Why?
Methotrexate - high chance of drug interactions
What 3 cancers are treated with 5-Fluorouracil? What animal is it not used in? Why?
- carcinoma of the GI tract, mammary gland, and lungs
- sarcoids
- cutaneous sqamous cell carcinoma
(in horses and dogs)
CATS - causes fatal neurotoxicity
What 2 cancers are treated with Cytarabine and Gemcitabine? What are 2 other therapeutic effects?
- lymphoreticular neoplasms
- CNS lymphoma
(in dogs and cats)
- myeloproliferative disease (can cause myelosuppression)
- granulomatous men
What antimetabolite has the ability to cross the BBB? How does this affect its therapeutic usage?
Cytarabine
can be used to treat neoplasms in the brain
What 3 cancers are treated with 6-Mercaptopurine and 6-Thioguanine?
- acute lymphocytic leukemia
- granulocytic leukemia
- lymphosarcoma
(in dogs and cats)
What is the mechanism of action of the 2 classes of microtubule targeting agents?
- VINCA ALKALOIDS prevent microtubule assembly
- Vincristine*
- Vinblastine
- Vinorelbine - TAXANES prevent microtubule disassembly
- Paclitaxel (Taxol)
- Docetaxel
(M PHASE)
What 3 cancers are treated with Vincristine?
- lymphoreticular neoplasms
- carcinomas, sarcomas
- transmissible venereal tumors
(in dogs and cats)
What 2 cancers are treated with Vinblastine?
- lymphoma
- mast cell tumors
(in dogs and cats)
What cancer is treated with Vinorelbine?
pulmonary carcinoma in dogs and cats
What 2 cancers are being investigated to be treated with Paclitaxel? What is another possible therapeutic use?
- mammary carcinoma
- osteogenic osteosarcoma
(in dogs)
histiocytosis
How are plant alkaloids administered? What does this entail?
IV
it is distributed to all but the CNS
What are the 2 mechanisms of action of anti-tumor antibiotics? What part of the cell cycle do they work on?
- bind to DNA and cause DNA fragmentation via generation of free radicals
- mitotic and topoisomerase II inhibitor
G2-M
What 2 antibiotics are used as anti-tumor drugs? Where do they act?
- Bleomycin - G2 specific, induces DNA damage
- Etoposide - G2-M specific, topoisomerase II inhibitor