Flood Chapter 42 Flashcards
A broad range of chemicals (drugs) aimed at treating cancer by eradicating malignant cells anywhere in the body are referred to as
Chemotherapy
Effectiveness of chemotherapy requires that there be complete destruction (total cell kill) of all cancer cells because?
a single surviving cell with the ability to divide can give rise to sufficient progeny to ultimately kill the host.
Harnessing our intrinsic immune surveillance system has become more and more a part of contemporary investigations of cancer and its treatment because?
The role of the immune system in identifying and eliminating foreign tumor cells has gained increasing recognition
The use of several chemotherapeutic drugs (also called antineoplastic drugs) concurrently or in a planned sequence is commonly done in efforts to?
eradicate even small residual tumor cell populations that have survived treatment with a single or previous agent.
What are the characteristics of drugs used in combination chemotherapy regimens
Use the largest tolerated doses of each chemotherapeutic drug
Drugs that work via different mechanisms
Drugs that do not share similar toxic effects
What is the advantage of using combination chemo agents with different MOA
Using a combination of agents that have different mechanisms decreases the chances that drug-resistant tumor cell populations will emerge.
Chemotherapeutic drugs used in combination are usually administered over short periods at specific treatment intervals rather than as continuous therapy. This is because?
Empiric observation that normal cells usually recover more rapidly from a pulse of maximal chemotherapy than do malignant cells.
Immunosuppression is less profound with intermittent administration of chemotherapy.
Even if all cells in a tumor are sensitive to a drug, a single dose of the drug is not usually sufficient to kill the typically hundreds of millions of cells that are present in patients with cancer.
With rare exceptions, the optimal dose of chemotherapeutic drugs requires repetitive dosing because?
Even if all cells in a tumor are sensitive to a drug, a single dose of the drug is not usually sufficient to kill the typically hundreds of millions of cells that are present in patients with cancer.
Malignant cells are often characterized by?
rapid division and synthesis of DNA.
Most conventional chemotherapeutic drugs exert their antineoplastic effects on cells that are?
actively undergoing division (mitosis) or DNA synthesis.
What affects how drugs are scheduled and combined for maximal effect.
The biology of the cancer under treatment
Cell cycle specificity of agents
Which cancers are slow-growing malignant cells with a slow rate of division, and often unresponsive or at best partially responsive to conventional chemotherapy.
carcinoma of the lung and colon
What cells are more vulnerable to the toxic effects of chemotherapeutic drugs.
Rapidly dividing normal cells like the cells found in the;
bone marrow
gastrointestinal mucosa
skin, and hair follicles
Clinical manifestations of toxicity caused by chemotherapeutic drugs represent activity at normal rapidly dividing cells and often include?
myelosuppression (leukopenia, thrombocytopenia, or anemia), nausea vomiting diarrhea mucosal ulceration dermatitis and alopecia
The most common toxicity that leads to temporary or permanent withdrawal of chemotherapy is?
Myelosuppression
The dose-limiting factor for many chemotherapeutic drugs is?
Myelosuppression
Drug-induced myelosuppression is usually irreversible. True/False?
is usually reversible with discontinuation of the chemotherapeutic agent.
Resistance to chemotherapeutic drugs often occurs and has many causes, these include?
Induction of drug-metabolizing enzymes in the liver, other tissues, or tumor cells, accelerating drug conversion to nontoxic metabolites.
Many solid tumors grow so rapidly that portions of the tumor are poorly vascularized, preventing therapeutic concentrations from reaching many target cells.
In poorly perfused areas of some tumors, cells remain resistant to chemotherapeutic drugs because of relative hypoxia.
Hypoxia causes resistance to both _______ and ___________
radiation
most chemotherapeutic drugs
What cancer is or susceptible to resistance due to hypoxia
malignancies susceptible to treatment with the mitomycins.
Side effects of cyclophosphamide ?
Hypersensitivity
Fibrosis Pneumonitis
Pericarditis, pericardial effusion =possible tamponade
N/V
Hemorrhagic Cystitis ( so if you see dysuria and hematuria d/c the drug)
Inappropriate secretion of arginine vasopressin (possible water intoxication)
Extravasation DOES NOT produce thrombophlebitis
Are patients with history of of chemo-induced nausea and vomiting prone to PONV ?
Not necessarily.
What antiemetics regimen have facilitated tolerance of emetogenic chemotherapeutic drugs ?
Serotonin antagonists (5HT3 antagonists ) as effective antiemetic
In addition to combination antiemetic has facilitated tolerance of emetogenic chemo drugs
The most commonly used Nitrogen Mustards are ? MMCC*
Mechlorethemine
Melphalan
Cyclophosphamide
Chlorambucil