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Antimetabolites-mechanism of action
- -cell-cycle specific analogues
- -they either falsely substitute for purines, pyrimidines, or folic acid
- -or they inhibit critical enzymes involved in the synthesis or function of these compounds
- -ultimately inhibit the synthesis of DNA, RNA, and proteins
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Folate Antagonists medications
-Methotrexate: used in treatment of solid tumors (breast, neck, and head); used in treatment of rheumatoid arthritis b/c it has immunosuppressive activity which inhibits lymphocyte multiplication; antidote is Leucovorin
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Antimetabolites (Adverse Effects)
- -hair loss, nausea, vomiting, diarrhea, and myeolosuppression
- -common general symptoms are fever and malaise
- -tumor lysis syndrome; may include hyperphosphatemia, hyperkalemia, and hypocalcemia; electrolyte abnormalities treated with diuretics such as mannitol, IV calcium supplementation,
- -severe: palmar-plantar dysesthesia; mild symptoms are painless swelling and erythema to painful blistering of the pt's palms and soles
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Antineoplastic Enzymes
- -indications: treatment of acute lymphocytic leukemia
- -adverse effects: impaired pancreatic function, can lead to hyperflycemia and severe or fatal pancreatitis
- -drug exmaple: asparaginase and pegaspargase
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Effects on Antineoplastic Drugs on Normal Cells
- -killing of normal cells of the GI mucous membrane may result in altered nutritional status, stomatitis, altered bowel function, poor appetitel, nausea, vomiting, and diarrhea
- -...or hair follicles leads to alopecia (loss of hair)
- -...in bone marrow results in dangerously low (life threatening) blood cell counts
- -...germinal epithelial cells leads to sterility (irreversible) in males, damages to the ovaries with amenirrhea in females, and teratogenic effects with possible fetal death
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interventions for stomatitis
- -oral hygiene before and after eating
- -avoid lemon, glycering, undiluted peroxide, and alcohol containing products b/c of drying/irritating effects
- -use soft bristle tootbrush and solutions of warm saline
- -pt's with dentures, remove and clean frequently, wear at mealtimes only if severe stomatitis
- -helpful to use otc saliva substitutes or sugarless candy/gum to stimulate saliva flow
- -avoid spicy, acidic, hot foods, alcohol, and tobacco
- -if white patches noted oral antifungal suspensions may be ordered
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Mitotic Inhibitors: Adverse Effects
- -hair loss, nausea and vomiting, myelosuppression
- -liver, kidney, lung toxicities
- -convulsions
- -extravasation
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Topoisomerase 1 Inhibitors (mechanism of action)
- -derived from camptothecin, a substance taken from a chinese shrub
- -inhibit proper DNA function in the S phase by binding to the DNA-topoisomerase 1 complex
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Topoisomerase 1 Inhibitors (indications)
- -primarily treat ovarian cancer and colorectal cancer, small cell lung cancer
- -shown to be effective in cases of metastatic ovarian cancer
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Topoisomerase 1 Inhibitors
- -bone marrow suppresion (predictable, reversible, manageable)
- -GI effects; nausea, vomiting, diarrhea
- -Irinotecan causes cholinergic diarrhea (delayed can occur 2 to 10 days after dosage)
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