Lecture 9 pharmacology of cytotoxins l Flashcards
What are the 7 pillars of cancer treatment?
- Surgery
- Radiotherapy
- Targeted therapy
- Chemotherapy
- Hormonal therapy
- Cell therapy
- Immunotherapy
Describe the action of cytotoxic drugs on cells.
Cytotoxic drugs act on dividing cells, mainly during the S phase, damaging DNA and causing apoptosis. They are anti-proliferative and some also act during the M phase.
Define biomarker.
A biomarker is a defined characteristic that is measured as an indicator of normal biological processes, pathogenic processes, or response to an exposure or intervention, including therapeutic interventions.
How can cancer treatment be improved?
Cancer treatment can be improved through stratified medicine, precision medicine, and personalized medicine approaches.
List the classifications of cytotoxic drugs.
Classic Anti-cancer agents, Alkylating agents, Anti-metabolites, Cytotoxic Antibiotic, Natural/Semisynthetic Product Agents.
Describe the mechanism of action of alkylating agents in pharmacology.
Alkylating agents prevent DNA replication and RNA transcription, induce mispairing of nucleotides, form bridges within DNA strands, and cross-link DNA with associated proteins.
What is the main target of alkylating agents in terms of DNA bases?
The main target of alkylating agents is N-7 Guanine, followed by N1 adenine, N3 cytosine, and N3 thymine.
How do nitrogen mustards like cyclophosphamide work as alkylating agents?
Nitrogen mustards contain 2-chloroethyl side chains that release Cl- ions forming carbonium ions, leading to cross-linkage between DNA strands.
Define the term ‘bifunctional’ in the context of alkylating agents.
Bifunctional alkylating agents have two reactive groups that can form intra and inter chain cross-linkages within DNA.
List three examples of platinum-based alkylating agents and their generations.
Cisplatin (1st gen), Carboplatin (2nd gen), Oxaliplatin (3rd gen) are examples of platinum-based alkylating agents.
Describe the difference between carboplatin and cisplatin in terms of ligands.
Carboplatin has a bidentate dicarboxylate ligand instead of two chloride ligands like cisplatin.
What is the mechanism of action of oxaliplatin on DNA bases?
Oxaliplatin forms intra and inter strand Pt-DNA crosslinks by reacting with DNA bases.
Define the reactivity of carboplatin with glutathione and metallothioneins compared to cisplatin.
Carboplatin has lower reactivity and slower DNA binding kinetics with glutathione and metallothioneins compared to cisplatin.
How does oxaliplatin differ from cisplatin in terms of safety profile and anti-cancer activity?
Oxaliplatin has a better safety profile and broad-spectrum anti-cancer activity compared to cisplatin.
Do carboplatin and oxaliplatin show any similarities in their toxicity profiles?
Both carboplatin and oxaliplatin have better toxicity profiles compared to cisplatin.
