chemotherapy (kē'mōthĕr`əpē), treatment of disease with chemicals or drugs drugs, substances used in medicine either externally or internally for curing, alleviating, or preventing a disease or deficiency. At the turn of the century only a few medically effective substances were widely used scientifically, among them ether , morphine ,
..... Click the link for more information. . One chemotherapeutic approach is the development of selectively toxic substances, i.e., substances that can destroy or inhibit infecting organisms or, as in cancer, malignant tissue, but do not damage normal host tissue. In treating infection, selectively toxic agents may block a biochemical reaction necessary to the viability of the pathogen but not to that of the host; for example, penicillin penicillin, any of a group of chemically similar substances obtained from molds of the genus Penicillium that were the first antibiotic agents to be used successfully in the treatment of bacterial infections in humans.
..... Click the link for more information. blocks synthesis of bacterial cell walls, a component animal cells lack. Other chemotherapeutic substances differentially affect biochemical reactions in different tissues; thus antimetabolites such as methotrexate and Cytoxan Cytoxan (sītŏk`sĭn), trade name for the drug cyclophosphamide, used to inhibit growth of tumors and rapidly proliferating cells.
..... Click the link for more information. are more toxic to rapidly proliferating cells such as those associated with cancer than to normal cells. Other drugs act in various ways to produce effects that initiate or enhance some normal body function; for instance, neostigmine blocks the action of an enzyme limiting transmission of nerve impulses and thereby acts as a nervous system stimulant. The usefulness of chemotherapeutic agents also depends on their pharmacological action, e.g., their rate of absorption, rapidity of action and rate of excretion, degree of storage in the body, effects of products of their metabolic breakdown, and potential for causing hypersensitivity hypersensitivity, heightened response in a body tissue to an antigen or foreign substance. The body normally responds to an antigen by producing specific antibodies against it. The antibodies impart immunity for any later exposure to that antigen.
..... Click the link for more information. reactions. Some drugs are given prophylactically, to prevent infection, e.g., penicillin is given to rheumatic fever patients to prevent reinfection by the causative organism, the streptococcal bacterium.

chemotherapy

Treatment of diseases, including cancer, with chemicals. Some cancer drugs interfere with cancer-cell division or enzyme processes. However, they have serious side effects, attacking some healthy cells and reducing resistance to infection. Certain steroids are used to treat breast cancer and prostate cancer, leukemia, and lymphomas. Derivatives of plants such as periwinkle (vincristine, vinblastine) and yew (taxol) have been found effective against Hodgkin disease, leukemia, and breast cancer.

chemotherapy

treatment of disease, esp cancer, by means of chemical agents

chemotherapy (redirected from cytotoxic drug)

chemotherapy

chemotherapy
(redirected from cytotoxic drug)