Anti-cancer drugs Flashcards
(26 cards)
What is the mechanism of action of alkylating agents?
Insert alkyl group, usually a carbonium ion, that cross-links adjacent bases in DNA, particularly G, as well as proteins. This causes stress, breaking the strand and resulting in apoptosis. Cycle non-specific. Cross-linking between strands is more desirable.
List four groups of classic cytotoxic agents.
Alkylating agents
Antimetabolites
Plant alkaloids
Hormonal agents antagonists
List two types of novel anticancer agents.
Monoclonal antibodies
Immunomodulating agents
List types of supportive therapy.
Analgesics, antidepressants, diet.
What is the mechanism of action of antimetabolites?
Block DNA synthesis by substituting nucleotides. S phase inhibitors.
List three targets of antimetabolites.
Folate, pyrimidine bases (C, T), purine bases (A, G)
What is the mechanism of action of plant alkaloids/mitotic poisons?
Inhibit either microtubule function or topoisomerase. M phase inhibitors.
List two hormone modulators used in breast cancer.
SERMS and aromatase inhibitors (inhibit oestrogen release from adipocytes)
List two hormone modulators used in prostate cancer.
Anti-androgens, gonadotrophin-RH analogues (reduce endogenous LH release )
Which hormone modulators are used for blood-borne cancers?
Glucocorticoids
What are common adverse effects of classic cytotoxic agents?
Alopecia, skin blistering and necrosis, GI sores (stomatitis) and mouth inflammation (mucositis), nausea and vomiting (chemo-trigger zone), infertility (particularly sperm), bone marrow suppression, organ toxicity.
Which organs are affected by organ toxicity of classic cytotoxic agents?
Heart - dysrhythmia, altered contractility, acute-chronic heart failure
Nervous system - targeting microtubules affects axonal transport
Kidneys - renal failure
Urinary bladder - haemorrhagic cyctitis
List three drug groups used to manage ADRs of classic cytotoxic drugs?
Antiemetic drugs
Colony stimulating factor (replenishing blood cells)
Organ toxicity drugs for haemorrhagic cystitis
Which antiemetic drugs are used in managing ADRs of classic cytotoxic agents?
Dopamine recetor antagonist (metoclopramide)
Serotonin receptor antagonist (ondansetron) - best
Neurokinin (substance p) receptor antagonist (aprepitant)
Glucocorticoids (dexamethasone)
Which colony stimulating factors are used in managing ADRs of classic cytotoxic agents?
Filigrastim (WBCs, particularly neutrophils)
Erythropoietin (RBCs)
When is mesna used in managing ADRs of classic cytotoxic agents?
When alkylating agents are used to reduce haemorrhagic cyctitis without affecting therapy.
List 5 types of novel anti-cancer agents.
Monoclonal antibodies
Immunomodulating agents (biological response modifiers, cytokine treatment)
Inhibitors of intracellular signalling molecules (tyrosine kinase inhibitors, serine-threonine kinase inhibitors)
Sensitising agents
List two monoclonal antibody drugs and their mechanism of action.
Rutiximab - anti-CD20 when over-expressed on B cells in non-Hodgkin’s lymphoma, triggering B cell lysis.
Trastuzumab (Herceptin) - binds to human epidermal growth factor 2 (HER2) when over-expressed in breast cancer
Attachment of cytotoxic agent to antibody
List two biological response modifiers and their mechanism of action.
Interferons - augment the cytotoxicity of immune cells to inhibit proliferation and alter antigen expression of tumour and immune cells.
IL-2 - sensitise patient’s lymphocytes in-vitro as IL-2 stimulates lymphocyte proliferation and cellular immunity, not first-line
What is the mechanism of action of inhibitor’s of intracellular signalling molecules?
Bind to kinase’s ATP site
Some also inhibit angiogenesis
When are kinase inhibitors used?
Selected leukaemia and GI tumours
Give an example of an immunisation using sensitising agents.
BCG for TB
List three complications of novel anti-cancer agents.
Drug resistance, tumour cell sanctuaries (tumour in inaccessible site), dose exhaustion.
How can drug resistance be overcome?
Multiple cytotoxic drug therapy, drugs with different actions, drug holidays
