Chemotherapy Agents

Characteristics of Cancer

-Damage/mutation of genes

-Rapid, uncontrolled proliferation

-Less mature and loses function

-Invades nearby tissues for growth

Metastatis

Abnormal cells from one site travels to distant site and forms new tumors (e.g. breast cancer → brain)

Cell cycle nonspecific (CCNS)

Cytotoxic in any phase of reproductive cancer cells

Cell cycle specific (CCS)

Cytotoxic in specific phase of cell reproductive cycle

G0 (resting phase)

Phase where cell is at rest, no preparations to divide, mature cells rest here; chemo can’t affect this phase

G1 (growth 1)

Phase where cell grows, makes protein, and prepares enzymes for DNA replication

S (synthesis)

Phase where DNA is duplicated

G2 (growth 2)

Phase where cells continuously grow, DNA checked for errors, and prepares for mitosis

M (mitosis)

Phase where cell divides into 2 identical daughter cells

Antineoplastic agents that are nonspecific

Alkylating agents, antitumor antibiotics, hormones, hormone inhibitors

Combination of Chemo

Uses multiple drugs that target different phases to increase chance of eliminating mutated cell and reduces drug resistance

Adverse Effects of Anticancer Drugs

NV, stomatitis, anorexia, alopecia, immunosuppression, fatigue

Prototype of Alkylating Agents

Cyclophosamide (Cytotoxan), Cisplatin (Platinol)

MOA of Cyclophosamide (Cytotoxan)

Adds alkyl group → DNA cross links and strand breaks → prevents replication → apoptosis

-CCNS; works in g0

Indications for Cyclophosamide (Cytotoxan)

Broad spectrum for lymphomas, leukemias, pancreatic and reproductive neoplasms

Adverse Effects of Cyclophosamide (Cytotoxan)

Bone marrow suppression, alopecia, hematuria (metabolite acrolein irritates bladder)

Prototype of Cytotoxic and Antitumor Antibiotics

Doxorubicin (Adriamycin)

MOA of Doxorubicin (Adriamycin)

Blocks DNA synthesis by binding to DNA and intercalating, causing strand breakage

-CCNS

Indications of Doxorubicin (Adriamycin) — Cytotoxic Antibiotic

Solid tumors and hematologic malignancies (leukemia, lymphoma)

Adverse Effects of Doxorubicin (Adriamycin) — Cytotoxic Antibiotic

Bone marrow suppression, alopecia, NO hematuria

Indications of Doxorubicin (Adriamycin) — Antitumor Antibiotics

-Solid tumors (bone, bladder, breasts, ovary, lungs)

-Neuroblastoma (cancer of immature nerve cells; adrenal glands)

Adverse Effects of Doxorubicin (Adriamycin) — Antitumor Antibiotics

Bone marrow suppression, Cardiotoxicity

Prototype of Antimetabolites

Methotrexate (MTX); Mercaptopurine (6-MP) & cladribine; Cytarabine (Ara-C)

MOA of Methotrexate (MTX)

Folic acid analog that disrupts metabolic pathway needed for cancer cells to replicate

-Same structure as folic acid (inhibits DHFR competitively)

-S phase

Prototype of Purine Analog

Mercaptopurine (6-MP), Cladribine

MOA of Mercaptopurine (6-MP), Cladribine

Blocks DNA synthesis by mimicking purine bases (adenine, guanine) and competes with them in DNA/RNA

-S phase

Prototype of Pyrimidine Analog

Cytarabine (Ara-C)

MOA of Cytarabine (Ara-C)

Prevents DNA replication by mimicking pyrimidine bases (cytosine, thymine) and competing against them

-S phase

Prototypes of Hormone and Hormone Antagonists

Estrogen & Tamoxifen; Testosterone & Dexamethasone (palliative)

MOA of Estrogen and Tamoxifen

Estrogen receptor antagonist in breast tissue → prevents estrogen-dependent breast cancer from developing

MOA of Hormone Antagonists

Blocks substances (hormones) needed for tumor growth

Indications of Estrogen and Tamoxifen

Breast cancer (estrogen dependent), Prostate cancer (androgen-senstiive), palliative care

Adverse Effects of Estrogen and Tamoxifen

Varies by drug (menopausal symptoms, thromboembolism, fluid retention, hormonal effects)

Prototype of Antineoplastic Enzymes

Asparaginase

MOA of Asparaginase

Blocks DNA synthesis by converting amino acid asparagine into aspartic acid + ammonia

-G phase (protein synthesis before DNA replication)

Indications of Asparaginase

Treats acute lymphoblastic leukemia (ALL)

Adverse Effects of Asparaginase

Impaired pancreatic functions, pancreatitis, hyperglycemia

Three Categories of Natural Products

Vinca alkaloids (vincristine), Taxenos (Taxol), Topoisomerase inhibitors (Etoposide)

Prototype of Vinca Alkaloids

Vincristine (Oncovin)

MOA of Vincristine (Oncovin)

Disrupts mitotic spindle formation by binding to tubulin, preventing microtubule formation

-M phase

Indications of Vincristine (Oncovin)

ALL, lymphomas

Adverse Effects of Vincristine (Oncovin)

Neurotoxicity (neuropathy, numbness, weakness); takes several months to resolve

General Adverse Effects of Chemotherapy

-Bone marrow suppression (WBCs, RBCs, platelets)

-Rapidly dividing cells (GI epithelial cells — stomatitis, ulcers, NVD; Alopecia)

Nadir

Lowest point in WBC count after chemo (highest risk of infection); pt must wear mask to protect themsleves

Anemia Nursing Care

Focuses on minimizing energy expenditure (rest, high carb+protein diet)

Thrombocytopenia Nursing Care

Minimizes trauma to mucosal membranes and tissue to prevent bleeding

Nausea/Vomiting Nursing Care

-Pre-medicate 30-60 mins before anticipated nausea

-Avoid favorite foods on day of chemo

-Avoid odors

Mucositis/Stomatitis (mouth) Nursing Care

-Look for inflammation, ulcers, white patches

-Gentle oral care and avoid salt/mouthwash

-Avoid strong foods (citrus, temps, spicy, fried, raw)

Anorexia Nursing Care

-Small frequent meals, high protein+carbs, avoid fatty and fried foods

-Soft, cold foods to soothe stomatitis

Alopecia

-Educate on hair loss (6-9 months temporary)

-pH balanced shampoo

-Avoid bleach, hairspray, heat styling tools that damage hair

Extravasation

-Leakage of agents from IV site

-Vesicants can cause permanent damage to nerves, muscles, tendons

Vesicant

Severe tissue blisters, irritation, necrosis

Post chemotherapy

IV lines, tubing, gloves, gowns, vials, and meds are considered hazardous and must be placed in designated chemotherapy waste containers

Biological Response Modifiers

Stimulates body’s immune system to kill tumor cells (cell-mediated response)

-Macrophages, T cells, NK cells, polymorphonuclear leukocytes

Interferon activity

Enhances activity of macrophage and NK cells (antineoplastic and antiviral)

-AE = flu-like symptoms and fatigue

Interleukins (IL-Z)

Causes T cells to multiply and activates lymphokine-activated killer cell (LAK)

-recognizes and destroys cancer cells only

Epoetin alfa (Epogen)

Stimulates RBC production to reduce chemo adverse effects

Filgrastim (Neupogen)

Stimulates neutrophils (WBC) production to reduce chemo adverse effects