Antineoplastics Flashcards
how do antineoplastic drugs work
- drugs treat various types of cancers or neoplasms: abnormally growing cells; also treated by surgery and/or radiation therapy
- work on neoplasms: may be benign or malignant (chance to metastasize)
how does cancer chemotherapy work
- complex process
- use of chemical agents that act by different mechanisms
- cycles of treatment
what do antineoplastics do
- kill cancer cells through damaging cell DNA or interfering with DNA synthesis
- toxic: affect normal cells -> high incidence of adverse events, toxicity and teratogenicity
what are side effects of antineoplastics
- most common adverse side effects: nausea and vomiting
- other toxic effects: bone marrow suppression, leukopenia -> predisposes patients to serious infections and thrombocytopenia -> serious bleeding problems
- examples: cyclophosphamide, methotrexate, paxitaxel, bleomycin, tamoxifen
what are cell cycle specific antineoplastic agents
- primarily affect cells that are actively multiplying
what are cell-cyclic nonspecific agents
- kill cells that are actively multiplying or at rest
- more toxic to normal cells than the CCS agents, but good for slow-forming neoplasms
what is a major cause of cancer treatment failure
- drug resistance, resulting in drugs that do not work on the cells
how often are there dental complications with patients being treated with chemotherapy and all patients receiving radiation
- in about 40%
how is xerostomia treated in patients with chemo
- due to suppression of salivary function, usually not permanent so treatment is usually palliative
- uncomfy because there is no salivary lubrication and the mucosal tissues get ‘sticky’ – dry mucosa may also be more prone to bleeding
what are patients taking chemo more at risk for
- candidiasis and dental/root caries
how can we prevent caries in patients taking chemo
- neutral sodium fluoride rinse such as prevident rinse
what is mucositis
- stomatitis
- inflammation and ulceration
- small areas of the ulceration quickly become large areas due to the direct toxic effect of the antimetabolites
- difficult to prevent as well as treat: viscous lidocaine; chlorhexidine rinse
what is oral candidiasis
- aka thrush
- common due to an overgrowth of fungi because of reduced white blood cell count
- it may be more important to prevent rather than treat
- anesthetic solution will help reduce the pain
what are bacterial infections
- the primary concern with high bacteria levels is the increased incidence of bacteremia
- ## thus, the patient may be placed on antibiotics as a prophylaxis for effective endocarditis
why are bacterial infections see more common in cancer patients
- seen due to bone marrow suppression, which reduces the white blood cell count
how does chlorhexidine oral rinse help with cancer ptes
- reduce bacterial levels and helps with oral hygiene
what causes taste alterations in cancer ptes
- alterations in taste are commonly seen in the cancer patient
- .this may occur due to the drug’s ability to affect sensitive taste buds
what are limitations to dental tx for chemo ptes
- the majority of patients will have depressed white blood cells (neutrophils), which an increase the incidence of infections
- patients may also have low platelets, which may increase the incidence of bleeding
- antibiotics may be necessary when blood cell counts fall below 1500 mm3
- bleeding becomes significant when platelets fall below 100,000mm3
- there are some drug interactions with antineoplastic agents but there are not any dental drug interactions
- nausea and vomiting may be complication treatment of the patient
what are immunosuppressant drugs
- used in patients after receiving an organ transplant from another human being to prevent rejection of the organ
- these drugs are usually given together with glococorticosteroids
- immunosuppressant drugs include azathioprine, cyclosporine, and tacrolimus
- patients taking immunosuppressants will most likely develop hypertension and subsequently will also be taking an antihypertensive drug such as a calcium channel blocker (eg nifedipine), which may also cause gingival enlargement
- pretransplant dentistry: critical part for the pmts, evaluate for the dental infections before placed on the ‘list’
- cyclosporine causes gingival enlargement
- patient taking this drug will be taking it forever
- gingival enlargement can be controlled by frequent gingivectomy/gingivoplasty procedures and meticulous home care
- drugs that alter cytochrome P450 isoenzymes in the liver may alter the plasma levels of the cyclosporine
