drug action

Also found in: Dictionary, Thesaurus, Legal, Encyclopedia, Wikipedia.

drug action

the means by which a drug exerts a desired effect. Drugs are usually classified by their actions; for example, a vasodilator, prescribed to decrease the blood pressure, acts by dilating the blood vessels.

drug action

The function of a drug in various body systems.

Local: When the drug is applied locally or directly to a tissue or organ, it may combine with the cell's membrane or penetrate the cell. Its action may be (1) astringent when the drug causes the cell or tissue to contract, (2) corrosive when the drug is strong enough to destroy cells, or (3) irritating when too much of the drug combines with cells and impairs them.

General, or systemic: This type of action occurs when the drug enters the bloodstream by absorption or direct injection, affecting tissues and organs not near the site of entry. Systemic action may be (1) specific, when it cures a certain disease; (2) substitutive or replenishing, when it supplies substances deficient in the body; (3) physical, when some cell constituents are dissolved by the action of the drug in the bloodstream; (4) chemical, when the drug or some of its principles combine with the constituents of cells or organs to form a new chemical combination; (5) active by osmosis, caused by dilution of salt (also acids, sugars, and alkalis) in the stomach or intestines by fluid withdrawn from the blood and tissues; or by diffusion, when water is absorbed by cells from the lymph; (6) selective, when action is produced by drugs that affect only certain tissues or organs; (7) synergistic, when one drug increases the action of another; (8) antagonistic, when one drug counteracts another; (9) physiological, when the drug exerts a potentially beneficial effect similar to that which the body normally produces; (10) therapeutic, when the effect is to treat or repair diseased organs or tissues; (11) side active, creating an undesired effect; (12) empirical, producing results not proved by clinical or laboratory tests to be effective; or (13) toxicological, having a toxic or undesired effect, generally the result of overdose or long-term usage.

Cumulative: Some drugs are slowly excreted or absorbed so that with repeated doses an accumulation in the body produces a toxic effect. Such drugs should not be administered continuously.

Incompatible: Undesired side effects occur when some drugs are administered together. This may be due to the antagonistic action of one drug on others or to a physical interaction of the drugs that inactivates one of them (e.g., precipitation of some drugs mixed in intravenous fluids).

See also: action
References in periodicals archive ?
The first 40 Local Drug Action Teams rolled out in April this year and delivered local drug and alcohol forums for parents and students, mentoring and professional training for at-risk young people, school based reduction programs, and promoted the role of local sporting clubs.
Sue Maddison, head of drugs and social inclusion strategy for Stockton Drug Action Team, said: "This new post will add an additional focus, which will continue to ensure user/carer feedback remains a high priority in Stockton.
Will Formby, the Kirklees Drug Action Team planning and commissioning co-ordinator for young people, said: "This project is open to all schools in Kirklees and aims to prevent today's young people from becoming tomorrow's drug users by stepping in before a potential problem becomes acute.
On making contact with the Drug Action Team, part of the Birmingham Community Safety Partnership, Amy was given immediate support.
A Whitehall aide said that the high figure in the Wirral was because of a concentration of urban deprivation in and around Birkenhead, and the activities of drug action teams across the peninsula.
The Pharmacogenetics Research Network is intended to address this need to acquire basic research results and store the information in a knowledge base, which will lead to a more complete understanding of drug actions, clinical translation of the information, and future drug development.
Since the launch of the drug action teams in 1998, pounds 400million a year has been spent, but with no evidence of a drop in the demand for drugs.
We are applying these technologies to efficiently home in on meaningful links between the human genome and drug action, providing a clear pathway for streamlining drug development, discovering safer and more effective drugs, and developing gene- based products that pair patients with the most beneficial pharmaceuticals.
Pharmacology in Rehabilitation begins with a general overview of drug action in the human body and explains the basic terminology employed in descriptions of medications.
In the latest offensive against the scourge of ice, the first 40 Local Drug Action Teams have been announced to tackle the challenges being faced by their community caused by ice and other drugs.
Sefton's Drug Action team was commended for its targeted drug approach which puts offender management at the centre of its service.

Full browser ?