Cancer Flashcards
Methotrexate
MOA
* inhibits dihydrofolate reductase (the enzyme that converts into tetrahydrodolic acid)
* Apoptosis
* s-phase specific
* disrupts metabolic processes of cell replication
Therapeutic use
* cure for women with choriocarinoma
* active against non-hodgkin lymphoma and acute lymphocytic leukemia
* head and neck sarcoma
* RA
Adverve effects
* bone marrow suppression
* pulmonary infiltrates and fibrosis
* oral and GI ulceration
* N//V
* kidney injury
* adequate hydration and alkalinized urine
* fetal malformation and death
- can be administered PO, IM, IV, and intrathecally
Vincristine
- blocks mitosis during m-phase
- given IV
Therapeutic use
* Non-hodgkins & hodgkins lymphoma, acute lympocytic, wilms, rhabdomyosarcoma, kaposi, breast, bladder cancer
toxicity
* peripheral neuropathy
* nearly all pt. experience symptoms or motor and sensory nerve injury
- causes little bone marrow suppression
Neutrophil count
2500-7000
les than 500= critical
Neutropenia
- loss of neutrophils= infection
- Nadir= lowesst neutrophil count occurs between 10-14 days
Digestive tract injury
- Stomatitis- inflammation of oral mucosa
- good oral hygiene and bland diet
- Diarrhea- High fiber diet
- N//V- very severe (ONDANSETRON)
- Hyperuricemia- excessive lvl of uric acid in blood– risk of kidney damage
toxicities of cancer
- tissue damage
- reproduction toxicity
- bone marrow suppression (myelosuppression) –> most common dose limiting toxicity of many chemo agents
- Thrombocytopenia= (loss of platelets)= bleeding
- avoid harsh teeth brushing,
- take tylenol only
- Anemia= loss of erythrocytes
side effects of Chemo
neutropenic precautions or reverse isolation
- wash hands
- bathe
- brush teeth 2x day
- prevent constipation
- no tamps or douche
- no sharing of personal items
- avoid fresh flowers
- keep cooked and raw food seperate
- cook food all the way
- pasturized food
neutropenic precautions or reverse isolation
- wash hands
- bathe
- brush teeth 2x day
- prevent constipation
- no tamps or douche
- no sharing of personal items
- avoid fresh flowers
- keep cooked and raw food seperate
- cook food all the way
- pasturized food
handling chemo
- check for blood return
- assess IV site
- D/C if extravastion occurs
- previous radiation sites are to be avioded
chemotherapy
- major impediment to successful chemo is toxicity of drugs to normal tissue
- chemo drugs are more toxic to tissue with high growth fraction
- bone marrow
- skin
- hair follicules
- sperm
- GI tract
- toxicity to normal cells is dose limiting
- cure requires 100% kill… no way of knowing
sucessful chemo
- Absence of Truly early detection
- Pap test for cervical cancer – only one!
- Solid tumors respond poorly – low growth fracation.
- Debulking helps because many cells leave G0 stage.
- Drug resistance- DNA changes
- Heterogeneity of Tumor cells – subpopulations of dissimilar cells – not all tumor cells look the same
- Limited Drug access to tumor cells – CNS or the core of tumors – How vascular is it?
chemo modalities
- intermittent chemotherapy – goal 100% kill of neoplastic cells with limited injury to normal tissue. Normal cells have time to repopulate
- Combination chemotherapy – 2 or more chemo drugs.
- Suppression of drug resistance
Increased cancer cell kill
Reduced injury to normal cells
Guidelines for Drug selection – each drug should be effective by itself, have a different mechanism of action & minimal overlapping toxicities.
- Optimizing dosing schedules
- Regional drug delivery
- Intra-arterial, Intrathecal (bypasses BBB), Intracavity
