Table of Contents
Chemotherapy Basic Concepts
Chemotherapy is used to destroy malignant cells by interfering with the reproduction of cancer cell
Types of Chemotherapy
- Cell-cycle Specific chemotherapy
- Cell-cycle Nonspecific chemotherapy
Act at specific points in cycle of cell division (cell-cycle specific) or at any phase in cycle of cell division (cell-cycle nonspecific)
Affect any rapidly dividing cell within body, thus having potential for toxicity development in healthy, functional tissue (e.g., bone marrow, hair follicles, GI mucosa);
Combination therapy often is used to reduce the possibility of toxicity and maximize therapeutic effect (e.g., cyclophosphamide, Doxorubicin, Vincristine, prednisone)
Classification of Chemotherapy Drugs
Alkylating Agents
Cell-cycle nonspecific; attack DNA of rapidly dividing cells
Nitrosourea: carmustine
Nitrogen mustard: chlorambucil , cyclophosphamide
Inorganic heavy metal: cisplatin , carboplatin
Cell-cycle specific; work during “M” phase; interfere with mitosis
Example: Vincristine
Antibiotics Used For Chemotherapy
- Cell-cycle nonspecific; inhibit DNA and RNA synthesis of rapidly dividing tissue
Examples: mitomycin (Mutamycin), DOXOrubicin
Antimetabolites
- A Cell-cycle specific; inhibit protein synthesis in rapidly dividing cells during “S” phase
Examples: fluorouracil or 5-FU, hydroxyurea, methotrexate
Hormones
Tissue-specific; inhibit RNA and protein synthesis in tissues that are dependent on opposite (sex) hormone for development
Examples: androgens, estrogens (estramustine), progestins, steroids (prednisone), hormone antagonists (mitotane), cortisol antagonist, estrogen antagonist (anastrozole, tamoxifen citrate), and luteinizing hormone-releasing hormone agonist (leuprolide)
Monoclonal Antibodies
Exogenous antibodies produced in laboratory by combining specific cancer cells with antibody-producing B cells;
- Derived from different sources: mouse (murine), combination of mouse and human sources (chimeric), or humanized
Monoclonal Antibodies
- Examples:
- rituximab, for non-Hodgkin’s lymphoma;
- Trastuzumab; for certain types of breast cancer;
- gemtuzumab ozogamicin; for leukemia;
- Alemtuzumab; for B-cell chronic lymphocytic leukemia;
- ibritumomab tiuxetan; for B-cell non-Hodgkin’s lymphoma;
- Cetuximab for advanced colorectal cancer
Other Immune Agents
A Introduction of noncancerous antigens or other agents into body to stimulate production of lymphocytes and antibodies
Examples
1. Bacille Calmette-Guérin (BCG) vaccine (TICE BCG): provides active immunity
2. Interferon alfa-2a , interferon alfa-2b : suppresses cell proliferation
3. Filgrastim (Neupogen): granulocyte colony–stimulating factor
Miscellaneous Agents
- Leucovorin calcium: reduced form of folic acid; acts as antidote to folic acid antagonists
Paclitaxel: inhibits reorganization of the microtubule network that is needed for interphase and mitotic cellular functions; causes abnormal bundles of microtubules during the cell cycle and multiple esters of microtubules during mitosis
Chemotherapy Side Effects
- Anorexia, nausea, vomiting, Stomatitis (irritation of GI tract; quick uptake by rapidly dividing alimentary tract tissue)
- Diarrhea (irritation of GI tract; quick uptake by rapidly dividing alimentary tract tissue)
- Bone marrow depression (quick uptake by rapidly dividing myeloid tissue)
- Blood dyscrasias (neutropenia, anemia, and thrombocytopenia) resulting from bone marrow depression
- Alopecia (rapid uptake by rapidly dividing hair follicle cells)
- CNS disturbances (neurotoxicity)
- Hepatic disturbances (hepatotoxicity)
- Tumor lysis syndrome: the release of large quantities of breakdown products, causing hyperkalemia, hyperuricemia, hyperphosphatemia, and acute renal failure
- Acute renal failure (direct kidney toxic effect)
- Cardiomyopathy (irreversible myocardial toxicity, congestive heart failure [CHF], ventricular dysrhythmias)
- Metabolic abnormalities (hypercalcemia, hyperuricemia)
- Allergic reactions, anaphylaxis with BCG vaccine
Bleeding Precautions
- Use a soft toothbrush and brush gently.
- If the platelet count is extremely low, foam swabs should be used instead of a toothbrush.
- Report any bleeding of the gums.
- Use only electric razors.
- Minimize lab draws and intramuscular (IM) injections; apply pressure to all needle sticks for 3–5 minutes.
- Report any bruising, rashes, or bleeding.
- Check urine and stool for hidden blood.
- Avoid constipation.
- Do not allow drugs containing aspirin or anticoagulants
Neutropenic Precautions
1. No fresh fruit or vegetables allowed (causes intestinal bacteria growth).
2. No flowers allowed.
3. Limit visitors (absolutely no one with a cold or infection).
4. Enforce strict hand washing; visitors can wear mask and gloves.
5. Watch for signs of infection.
6. Assess lab values and temperature.
7. No rectal temperatures, suppositories, or enemas allowed.
8. Avoid urinary catheters.
9. Use only soft toothbrush (the mouth is the most frequent site of infection).
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