Week 1 - Chemotherapy Flashcards
what is chemotherapy
- pharmacologic treatment of cancer
what are chemotherapy drugs also called?
- antineoplastic drugs
how is chemotherapy categorized?
- split into 2 groups based on where in the cell cycle they work
1. cell cycle nonspecific
2. cell cycle specific - note: some drugs have characteristics of both
what are the 3 main goals of chemotherapy?
- cure
- control
- palliation
what is meant by palliation?
- relieve pain
- relieve obstruction
- improve sense of well being
describe the therapeutic index of chemotherapy
- these drugs have a very narrow therapeutic index
what is combination therapy?
- where a combo of drugs is given for treatment
what is the purpose of combination therapy?
- more effective than single-drug therapy
- allows us to work around the narrow therapeutic index of drugs by using a lower dose of more drugs to avoid side effects
what is an example of combination therapy?
RCVP for lymphoma
- rituximab
- cyclophosphamide
- vincristine
- prednisone
describe drug resistance related to chemo; what does this mean
- drug resistance occurs in almost all drugs over a period of time
- therefore, once we use a drug once, we cannot use it again
what is meant by dose limiting adverse effects?
- many chemo drugs cause dose-limiting adverse effects which are often intolerable
- this is why we give “rounds” of chemo
describe the effect chemo has on cells in general
- harmful to all rapidly dividing cells
- this means it is harmful to both cancer cells & healthy, normal human cells bc they are both dividing
which cells/tissues are most effected by chemo (3)? why?
- hair follicles
- GI tract cells
- bone marrow cells
- chemo targets all rapidly dividing cells & these are some of the fastest growing cells in the body
what does chemo’s effect on hair follicles cause?
- alopecia
what is alopecia?
- hair loss
what does chemo’s effect on GI tract cells cause?
- emetic potential
what is emetic potential?
- nausea & vomiting
- gastric upset
what does chemo’s effect on bone marrow cells cause?
- myelosuppression (bone marrow suppression)
what is nadir?
- lowest WBC count we are willing to accept before we have to stop giving chemo
what is extravasation
- leakage of an intravenously infused fluid onto the tissue around the site of infusion
describe the relation between extravasation & chemotheraoy
- most chemo is intravenously infused
- extravasation of chemotherapy causes significant skin & tissue breakdown
how does the relation between extravasation & chemo effect the care we provide?
- it is important to monitor IV lines
what are cell cycle specific drugs
- drugs that are cytotoxic during a specific cell-cycle phase
what are cell cycle-specific drugs used to treat?
- a variety of solid and/or circulating tumours
what are 2 categories of cell cycle-specific drugs
- antimetabolites
2. mitotic inhibitors –> vinca alkaloids
what is the MOA of antimetabolites?
- disrupt critical metabolic processes, such as disrupting DNA replication & formation
what phase of the cell cycle do antimetabolites typically work in?
- S phase
what are the 3 classes of antimetabolites?
- folate (folic acid) antagonists
- purine antagonists
- pyrimidine antagonists
what is a type of folate (FA) antagonist?
- methotrexate
list the 3 actions of methotrexate
- chemo effects
- immunosuppressive
- anti-inflammatory
what is the MOA of methotrexate in chemo therapy
- blocks the conversion of folic acid into its active form, which is required for many biochemical reactions
what conditions is methotrexate used for besides cancer
- rheumatoid arthritis
- psoriasis
what is the rescue med for methotrexate
- leucovorin
what is leucovorin
- folinic acid
- very similar to folic acid but not the same
why would we need to give leucovorin?
- used to avoid folate deficiency which can lead to anemia, etc.
- used to protect healthy cells so they can continue to produce folic acid
- helps reduce BMS
what are mitotic inhibitors? what phase do they work in?
- drugs that work in the M phase to prevent cell division
how are mitotic inhibitors obtained ?
- vinca alkaloids are derived from the periwinkle plant
- semisynthetic drugs are obtained from the mandrake (mayapple) plant
- some drugs are obtained from the yew tree
what are the 2 major groups of mitotic inhibitors?
- vinca alkaloids
2. taxanes
what is the prototype of vinca alkaloids
- vincristine (oncovin)
what is the benefit to vincristine (2)?
- its bone marrow sparing
- ideal for combo therapy
what is a con to vincristine?
- peripheral neuropathy is a major dose-limiting side effect
what are cell-cycle nonspecific drugs
- drugs that can act during any phase of the cell cycle, including G0
what are the 3 major classes of cell cycle nonspecific drugs?
- alkylating drugs
- cytotoxic antibiotics
- hormonal drugs
what is the MOA of alkylating drugs?
- kills & prevents cancer cells from reproducing thru alkylating DNA
what are the 3 major classes of aklyating drugs?
- nitrogen mustards
- nitrosoureas
- miscellaneous alkylators
what is the prototype of nitrogen mustards?
- cyclophosphamide (cytoxan)
what are cytotoxic antibiotics?
- natural substances produced by the mold streptomyces
- can also be synthetic
what is the difference between cytotoxic antibiotics & regular antibiotics?
- cytotoxic = only to treat cancer, too toxic to treat infections
what is the MOA of cytotoxic antibiotics
- act by intercalation = direct blockade of DNA synthesis
what are 2 types of cytotoxic antibiotics?
- bleomycin
2. doxorubicin
what is a common side effect of cytotoxic antibiotics? which type does not cause this?
- all cause BMS
- except bleomycin
what is the major adverse effect of bleomycin
- pulmonary toxicity
- can cause pneumonitis and pulmonary fibrosis
what is the major adverse effect of doxorubicin
- cardiotoxicity
- can cause heart failure
what is the MOA of hormonal drugs
- oppose the effects of hormones
- block the body’s sex hormone receptors
what are hormonal drugs used to treat?
- variety of neoplasms in men & women
- specifcally for breast & prostate cancer
how are hormonal drugs used most commonly?
- most commonly as an adjuvant & palliaitive therapy
- occassionally may be first choice for some cancers
what is are 2 classes are hormonal drugs?
- selective estrogen receptor modulators
2. estrogen receptor antagonist
what is the prototype for selective estrogen receptor modulators? what is the MOA?
- tamoxifen
- can cause receptor activation & blockade
what is tamoxifen considered the gold standard for?
- for endocrine treatment of breast cancer
what is the prototype for estrogen receptor antagonists? what is the MOA?
- fulvestrant
- pure estrogen receptor antgaonist
what is extravasation
- leaking of an antineoplastic drug into surrounding tissues during IV admin
what can extravasation result in?
- can result in permanent damage to nerves, tendons, muscles, and loss of limbs
- skin grafting & amputation may be necessary
describe prevention of extravasation
- thru Iv monitoring
what type of anti-inflammatory drug may be used for cancer treatment?
- prednisone
what is the 4th part of cancer therapy
- biologic response modifiers
- in addition to surgery, chemo, and radiation
what else might BRMs be used for
- autoimmune disorders
- inflammatory disorders
- infectious
what are 3 classes of BRMs?
- hematopoietic drugs
- interferons
- monoclonal antibodies
what is the MOA of hematopoietic drugs
- promote the synthesis of blood cell types by promoting the growth, differentiation, and function of their precursor cells in the bone marrow
how are hematopoietic drugs produced?
- thru rDNA technology
what are hematopoietic drugs used for?
- decrease the duration of chemo induced anemia, neutropenia, and thrombocytopenia
- enable higher doses of chemo
what are 3 types of hematopoietic drugs?
- epoetin alfa (epogen)
- filgrastim (neupogen)
- oprelvekin (neumega)
what is epoetin alfa?
- synthetic derivative of the hormone erythropoetin (hormone that stimulates RBC production)
what is the MOA of epoeitin alfa?
- promotes the synthesis of RBC
the nurse should monitor what after administering epoeitin alfa?
- HGB levels
2. bp
increased adverse effects are present with epoetin alfa when used by patients with _______
- higher than normal hgb –> blood can become too thick
what can occur with patients with higher-than-normal hemogloin when taking epoetin alfa?
- heart attack
- HF
- stroke
- death
what is filgrastim (neupogen)? what is its MOA?
- granulocyte colony-stimulating factor
- stimulates precursor cells for the type of WBCs known as granulocytes
what are granulocytes?
- neutrophils
- eosinophils
- basophils
what is oprelvekin (neumega)? what is its MOA
- aka interleukin (IL-11)
- stimulates megakaryocytes to become platelets
what are interferons?
- proteins with 3 basic properties:
1. antiviral
2. antitumour
3. immunomodulating
what are interferons used to treat?
- viral infections
- cancer
- autoimmune disorders
what viral infections are interferons used for?
- genital warts
- hepatitis
what autoimmune disorders are interferons used for
- multiple sclerosis
- & others
what are monoclonal antibodies? (MAB)
- use of synthetically made antibodies to target specific cancer cells
describe the effect of MABs on healthy cells
- minimal effect
- fewer, if any, adverse effects than traditional neoplastic meds
what are MABs used for?
- to treat cancers & rheumatoid arthritis
list 3 types of MABs used to treat cancer
- trastuzumab
- rituximab
- bevacizumab
list 1 MAB used to treat other disease processes such as rheumatoid arthritis
- infliximab
what cancer is trastuzumab good for?
- breast cancer (blocks HER2 receptor)
what cancer is rituximab good for? why>
- targeted therapy
- directed against CD20, an antigen found only on the surface of B lymphocytes
what is the classification of prednison
- corticosteroid
- cell cycle phase nonspecific
what is the MOA of prednisone
- disrupts the cell membrane
- inhibits synthesis of protein
- decreases circulating lymphocytes
- inhibits mitosis
- depresses the immune system
- increases feeling of well being
what is the MOA of cyclophosphamide
- damages DNA by causing breaks in the double strand helix
- alkylates DNA = cross-links & strand breakage
what cellular processes are interupted by cyclophosphamide?
- DNA and RNA synthesis
what is the MOA of vincristine
- interrupts cellular replication in mitosis @ metaphase
