| antineoplastic agent, alkylating | A class of drugs that differs from other alkylating agents used clinically in that they are monofunctional and thus unable to cross-link cellular macromolecules. Among their common properties are a requirement for metabolic activation to intermediates with antitumour efficacy and the presence in their chemical structures of n-methyl groups, that after metabolism, can covalently modify cellular DNA. The precise mechanisms by which each of these drugs acts to kill tumour cells are not completely understood. (12 Dec 1998) |
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| alkylating agent | <oncology, pharmacology> A reagent that places an alkyl group, for example propyl in place of a nucleophilic group in a molecule. Alkylating reagents include a number of cytotoxic drugs some of which react fairly specifically with N7 of the purine ring and lead to depurination of DNA, for example the agent ethyl ethanesulphonic acid and thus to mutagenesis. The drugs interaction with DNAand prevents the division of the cells. Examples of drugs include: busulphan, chlorambucil, cyclophosphamide, melphalan. (29 Sep 1997) |
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| antineoplastic agent | Agents inhibiting or preventing the growth of neoplasms, checking the maturation and proliferation of malignant cells. (12 Dec 1998) |
| antineoplastic agent, combined | The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form. (12 Dec 1998) |
| antineoplastic agent, hormonal | Antineoplastic agent that are used to treat hormone-sensitive tumours. Hormone-sensitive tumours may be hormone-dependent, hormone-responsive, or both. A hormone-dependent tumour regresses on removal of the hormonal stimulus, by surgery or pharmacological block. Hormone-responsive tumours may regress when pharmacologic amounts of hormones are administered regardless of whether previous signs of hormone sensitivity were observed. The major hormone-responsive cancers include carcinomas of the breast, prostate, and endometrium; lymphomas; and certain leukaemias. (12 Dec 1998) |
| antineoplastic agent, phytogenic | Agents, obtained from higher plants that have demonstrable cytostatic or antineoplastic activity. (12 Dec 1998) |
| alkylating agents | Highly reactive chemicals that introduce alkyl radicals into biologically active molecules and thereby prevent their proper functioning. Many are used as antineoplastic agent, but most are very toxic, with carcinogenic, mutagenic, teratogenic, and immunosuppressant actions. They have also been used as components in poison gases. (12 Dec 1998) |
| antibiotics, antineoplastic | Chemical substances, produced by microorganisms, inhibiting or preventing the development of neoplasms. (12 Dec 1998) |
| antimetabolites, antineoplastic | Antimetabolites that are useful in cancer chemotherapy. (12 Dec 1998) |
| antineoplastic | Inhibiting or preventing the development of neoplasms, checking the maturation and proliferation of malignant cells. Origin: Gr. Plassein = to form (18 Nov 1997) |
| antineoplastic and immunosuppressive agents | Collective grouping for substances used to arrest the proliferation of malignant cells and those that suppress the immune response. (12 Dec 1998) |
| antineoplastic drug | A drug that stops or slows the maturation and spread of tumour cells (benign or malignant). (09 Oct 1997) |
| adrenergic blocking agent | A compound that selectively blocks or inhibits responses to sympathetic adrenergic nerve activity (sympatholytic agent) and to epinephrine, norepinephrine, and other adrenergic amines (adrenolytic agent); two distinct classes exist, alpha-and beta-adrenergic receptor blocking agent's. (05 Mar 2000) |
| adrenergic neuronal blocking agent | A drug that prevents the release of norepinephrine from sympathetic nerve terminals; it does not inhibit the responses of the adrenergic receptors to circulating epinephrine, norepinephrine, and other adrenergic amines. (05 Mar 2000) |
| agent | <pharmacology> Any power, principle or substance capable of producing an effect, whether physical, chemical or biological. Origin: L. Agens = acting (18 Nov 1997) |
| agent, antihypertensive | As the name suggests, a drug aimed at reducing high blood pressure (hypertension). (12 Dec 1998) |