chemotherapy Flashcards
Different types of cytotoxic agents
1- Alkylating agents
2-Antimetabolites
3- Spindle poisons
4- Antimitotic antibiotics
Other systemic treatments
1-Hormone treatment
-Anti-oestrogen- Tamoxifen- aromatase inhibitor: used in breast cancer
-Anti- androgen- CPA/ Flutamide: used in prostate cancer
2-Targeted drugs
epidermal growth factor receptor -erlotinib/ gefinitib
vascular endothelial receptor
side effects of Chemotherapy
- nausea and vomiting: peripheral-enterochromaffin cell, 5HT3 receptor, serotonin released, vagal afferent central- area postema, NK1 receptor, dorsal vagal complex - alopecia - mucositis -pulmonary fibrosis -neuropathy -renal failure -myelosuppression- decrease in bone marrow function -myalgia- muscle pain -phlebitis- vein inflammation -sterility -cardiotoxicity
effects of combining drugs
1- Action of drug- synergistic, helps prevent resistance
2- safety- similar toxicity
Alkylating agents
- Alkyl groups allow covalent bond to be formed at guanine at N6 on DNA strand (WHEN DNA STRANDS ARE SEPARATED)
- Prevents DNA from being used as a template strand
- Can act at any stage of cell replication
- Can be overridden by preventing entry, disactivating it once it has entered the cell or by repairing damage it causes to DNA
e. g. cisplatin
Antimetabolites
- Similar to essential metabolites which are needed to start cell cycle
- They become part of nuclear material or they bind to enzymes
- Act at S
e. g. antagonise folic acid- METHOTREXATE
Spindle poisons
Vancoalkoids- inhibit spindle formartion by binding to tubules
Taxanes- promote spindle formation and freeze cell
-Act at M
Antimitotic antibiotics
Act at G1-G2
Anthracycline and non-anthracycline bind to membrane and alter permeability- they prevent DNA and RNA synthesis
-Flow of free radicals- disrupts DNA chain and prevents mitosis
-Metal ion chelation causes formation of cytotoxic compounds
-alylation blocks DNA replication
