What does therapeutic effect mean

In medical pharmacology, the science and study of how drugs produce their effects. Pharmacology , Pharmacokinetics , Therapeutics , Pharmacogenetics. The science and study of the inheritance of characteristic patterns of interaction between chemicals drugs and organisms. Pharmacogenetics involves identification and description of such patterns, discriminating them from non-heritable patterns, and elucidation of the mechanism of inheritance.

Pharmacogenetic studies illuminate many intraspecific and interspecific similarities, and differences in pharmacodynamic and pharmacokinetic mechanisms. The science and study of the factors which determine the amount of chemical agents at their sites of biological effect at various times after the application of an agent or drug to biological systems. Pharmakon — drug, and Logos — word is the study of drugs in all their aspects.

Pharmacy, although often confused with pharmacology, is, in fact, an independent discipline concerned with the art and science of the preparation, compounding, and dispensing of drugs.

Pharmacognosy is a branch of pharmacy that deals with the identification and analysis of the plant and animal tissues from which drugs may be extracted. The pharmacodynamicist, or pharmacologist, identifies the effects produced by drugs, and determines the sites and mechanisms of their action in the body.

The pharmacologist studies the physiological or biochemical mechanisms by which drug actions are produced. The pharmacologist also investigates those factors that modify the effects of drugs, i. Pharmacotherapeutics is the study of the use of drugs in the diagnosis, prevention, and treatment of disease states.

Toxicology is the study of drug effects that are inimical to health. The toxicologist may investigate such diverse problems as the effects of overdoses of pharmacotherapeutic agents; the diagnosis, treatment, and prevention of lead poisoning in the paint manufacturing industry; the possibility that criminal poisoning was the cause of an otherwise inexplicable death, etc. Pharmacology is a part of biology… Of all the vast number of pharmacologic reactions, those that the physician attempts to use for curative purposes are of the greatest interest and most deserved of study.

Meter and R. Therapeutics , Pharmacodynamics , Pharmacokinetics , Pharmacogenetics , Toxicology. Latin: I will satisfy. A drug preparation incorporated into an experiment with the intention that it have effects on the experimental system qualitatively similar to those expected of the independent variable. The positive control drug has two functions in an experiment: 1 to verify that the experimental system is indeed capable of undergoing the changes expected to follow manipulation of the independent variable.

If the system fails to respond to the positive control drug, its failure to respond to the independent variable is uninterpretable; 2 to serve as a basis for quantitative estimation of the relative efficacy of the independent variable. An expression of the activity of a drug, in terms of the concentration or amount needed to produce a defined effect; an imprecise term that should always be further defined see EC 50 , ED A special case of synergy q.

For example, although physostigmine has no acetylcholine-like activity of its own, it potentiates the actions of acetylcholine by inhibiting the enzymes responsible for the destruction of acetylcholine. Intensity of effect may be potentiated , duration of effect may be prolonged: potentiation and prolongation are independent phenomena, but frequently occur together. A chemical with little or no pharmacologic activity that undergoes change in the body into a more active material.

The change may be a result of biotransformation, or may occur spontaneously, in the presence of, e. The square of the reciprocal of the index of precision is the measure of the amount of information that can be delivered by the system. Specifically, precision is computed in several steps. First, the deviation of each observed value of output from the corresponding predicted value is squared; predicted values are determined from the curve relating input and output for all the data.

Intrinsic Activity , Affinity , Antagonism. A drug, chemical, or dosage form, etc. Even physical systems of measurement are based on reference standards. The use of reference standards is of particularly great importance to the design and interpretation of biological experiments. In biological experiments, particularly, variability and instability of the biological test system can markedly influence the apparent effects and effectiveness of substances being tested.

The degree to which the input-output relationship is reproducible if the relationship is studied repeatedly under comparable conditions.

For example, if a student took the same examination twice, or in two forms, would he get the same grade both times? If the same work were reviewed by two graders, would they both assign the same mark?

The likelihood that harm will result from exposure to a hazard. More generally, the probability that an event has occurred, or will occur, in members of a population under specified conditions, e. Risk is calculated by dividing the number of subjects who experience an event by the number of subjects in the population at risk. The risk, so calculated, is one of the bases used to estimate the likelihood that the event will occur in the future, the predicted risk.

Risk, calculated as described, also indicates the probability that any individual subject in the population at risk experienced the event. For a meaningful estimate of risk following exposure of subjects to some hazard , it is necessary to have carefully defined the harm that was done, to have characterized the population at risk, and to have specified the conditions of exposure.

The statistical techniques used to estimate risks and to compare them are, generally, the techniques used in epidemiology. Perceived risk is the subjective assessment of the importance of a hazard to individuals or to groups of individuals, For example, hazards that affect children generally have higher perceived risks than those that tend to affect adults.

Hazards that produce fatalities grouped in time and space e. Perceived risks are not necessarily correlated with the risks, for the same hazards, measures by epidemiologic techniques.

Risk management is the effort to reduce the likelihood that a hazard will produce harm. Risk management may involve decreasing the size of the population at risk e. The capacity or propensity of a drug to affect one cell population in preference to others, i. Selectivity can be measured or described by means of such numbers as the Therapeutic Index, or the Standardized Safety Margin: not infrequently one wishes to express selectivity of drug action with respect to two potentially beneficial effects, or two potentially toxic doses, or two toxic doses, instead of one each.

Selectivity is generally a desirable property in a drug, e. Sometimes, selectivity of action is virtually precluded by the nature of the drug, e. Sometimes selectivity of action for cells within an organism is not necessarily desirable, as in the case of certain economic poisons, i.

They describe separate phenomena, each of which deserves an unambiguous name. The ability of a population, an individual or a tissue, relative to the abilities of others, to respond in a qualitatively normal fashion to a particular drug dose.

The smaller the dose required to produce an effect, the more sensitive is the responding system. Conversely, the drug would appear to be extraordinarily potent or impotent in such a patient.

If a patient manifested an allergic response after raking aspirin, he would be considered hypersensitive to aspirin, regardless of whether the aspirin afforded him relief from pain, and regardless of the size of the dose required to elicit the allergic response.

Such a patient might be simultaneously hypersensitive to aspirin, and insensitive to aspirin, acting as an analgesic agent. Hypersensitivity is a property ascribed to a subject in a particular immunologic state. Drug effects which are not desirable or are not part of a therapeutic effect; effects other than those intended.

For instance, in the treatment of peptic ulcer with atropine, dryness of the mouth is a side effect and decreased gastric secretion is the desired drug effect. If the same drug were being used to inhibit salivation, dryness of the mouth would be the therapeutic effect and decreased gastric secretion would be a side effect. Pharmacological side effects are true drug effects.

The existence of spare receptors reflects a circumstance in which the maximum effect produced by an agonist is limited by some factor other than the number of activated receptors. Whether or not a system has spare receptors depends upon the nature of the receptor and its coupling to the measured response, the number of receptors, and the intrinsic activity of the agonist. The capacity of a drug to manifest only one kind of action.

A drug of perfect specificity of action might increase, or decrease, a specific function of a given cell type, but it would not do both. Nicotine is not specific in its actions in autonomic ganglia; it both stimulates and depresses ganglionic function by a number of means. Atropine is quite specific in only blocking the actions of acetylcholine at certain receptors; in general atropine does not stimulate cellular activity when it combines with receptors, nor does it block interaction with receptors of agonists other than acetylcholine.

In affecting exocrine glands, acetylcholine itself is very specific, in that it causes only stimulation or secretion; acetylcholine, at the same time, is non-selective in its action, in that stimulation of all exocrine glands is produced by about the same dose of acetylcholine. Selectivity is concerned with site of action ; specificity , with the kinds of action at a site. The therapeutic index q. Clinically, the standardized safety margin probably has greater practical meaning than does the therapeutic index, and, unlike the therapeutic index, the meaningfulness of the standardized safety margin does not depend on the parallelism of the dose effect curves from which the LD 1 and ED 99 are inferred.

The standardized safety margin more frequently than the therapeutic index can sometimes be computed from clinical data not involving lethal effects, e. See: Foster, R. An extreme and high degree of sensitivity to a drug or chemical. Usually a high degree of sensitivity induced by some specific procedure such as denervation, administration of another drug, etc. Sensitivity to a drug, of some degree, is inherent in every organism; supersensitivity is a state that has had to be produced in the organism.

In the supersensitive subject, the actions of the drug are qualitatively like those observed in a subject of normal sensitivity, and unlike those produced in a subject who is hypersensitive to the drug. A mutually reinforcing drug interaction such that the joint effect of two drugs administered simultaneously is greater than the sum of their individual effects.

Synergism is distinguished from additivity , in which the joint effect of two drugs is equal to the sum of their individual effects. A point in time or a time interval; frequently a time interval following administration of a drug or the time interval between doses of a drug. Specific times of interest may be indicated by subscripts, e.

The idea of half-life is legitimately applied only to the case of a drug eliminated from body fluid according to the laws of first-order reaction kinetics. Half-Life , b , k el , First-Order Kinetics. A decline in the response to repeated applications of agonist, typically occurring over a relatively short time scale seconds to hours.

See also Desensitization , Tolerance. The therapeutic index is ordinarily calculated from data obtained from experiments with animals.

As in comparing ED 50 s from two different drugs, the comparison of the LD 50 and ED 50 therapeutic index is most meaningful when the dose-effect curves from which the ED 50 and LD 50 are inferred are parallel.

The therapeutic index is a measure of drug selectivity, and analogous index numbers are frequently computed to measure selectivity that does not involve lethal effects. For example, to measure the selectivity of a drug potentially useful in the treatment of epilepsy, the ED 50 for producing ataxia in mice might be compared to the ED 50 for abolishing electrically-induced convulsions in mice. The science and techniques of restoring patients to health. Properly, therapeutics has many branches, any or all of which may be needed in the treatment of a specific patient.

In addition to pharmacotherapeutics or drug therapy, there exist coordinate fields of therapeutics such as surgical therapy, psychotherapy, physical therapy, occupational therapy, dietotherapy, etc. Drugs are commonly considered capable of participating in one or more of the following general kinds of therapy:. A single drug may have two or more therapeutic effects in the same patient at the same or different times, or in different patients.

A dose of drug just sufficient to produce a pre-selected effect. Frequently, and improperly, restricted to the dose just sufficient to produce a minimal detectable effect. Median Effective Dose , Sensitivity , Potency.

The graphical representation of the relationship — for a given drug and a given biological system — between concentration or dose and latency or latent period: the period of time elapsing between the time the dose is administered and the time a given effect is produced.

Time-concentration curves tend to be hyperbolic in form: as dose increases latency decreases and vice versa. Latency is an inverse function of concentration. But the hyperbolic relationship never approaches the axes as asymptotes; there is always a concentration below which the drug is ineffective, regardless of the duration of exposure of the tissue to the drug, and there is always a finite interval between the time of exposure to the drug and the time the response occurs.

The time-concentration curve is analogous to the strength-duration curve that the physiologist uses to determine rheobase and chronaxie.

It is characteristic of true drug effects that a generally hyperbolic relationship exists between dose and latency. If, with increasing doses of material, a time-concentration curve and a dose-effect curve cannot be demonstrated, one cannot conclude that the material is responsible for the effects observed. A condition characterized by a reduced effect of a drug upon repeated administration. In some cases, it may be necessary to increase the dose of the drug to attain the same effect, or the original level of effect may be unattainable.

Tolerance typically develops over days to weeks, and is distinguished from tachyphylaxis , a more rapid decline in the effect of a drug. Tolerance can result from multiple mechanisms, including changes in drug metabolism and alteration in the number or responsiveness of receptors see desensitization.

A non-habitual drinker who is unaffected by several drinks of whisky downed in rapid succession is probably insensitive to alcohol rather than tolerant to its effects. Addiction , Sensitivity , Habituation , Dependence. Responses to drug that are harmful to the health or life of the individual. Toxic effects are not side-effects in the case of pesticides and chemical warfare agents.

Toxic effects may be idiosyncratic or allergic in nature, may be pharmacologic side effects, or may be an extension of therapeutic effect produced by overdosage.

An example of the last of these is the apnea produced by an anesthetic agent. The scientific discipline concerned with understanding the mechanisms by which chemicals produce noxious effects on living tissues or organisms; the study of the conditions including dose under which exposure of living systems to chemicals is hazardous.

Hazard , Pharmacology , Toxic Effects. A simplified model of receptor activation by agonists. Agonists bind preferentially i. The United States Pharmacopoeia is a reference volume, published every five years by the U. Pharmacopoeial Convention, which describes and defines approved therapeutic agents, as well as sets standards for purity, assay, etc. Agents are included on the basis of their therapeutic value. The U. The purposes of the Pharmacopoeia , as described in the Preface to the first edition in by Dr.

Jacob Bigelow, are to :. Test Your Vocabulary. Can you spell these 10 commonly misspelled words? Love words? Need even more definitions? Homophones, Homographs, and Homonyms The same, but different. Ask the Editors 'Everyday' vs. What Is 'Semantic Bleaching'? How 'literally' can mean "figuratively".

Literally How to use a word that literally drives some pe Is Singular 'They' a Better Choice? The symptoms can be predicted. They can turn out to be fatal for patients. Their effect can be reduced. Therapeutic effect. Creating art, indulging in self-care, and other meditative activities are often considered to be therapeutic. It may sometimes be important to categorize a specific therapeutic method of treatment as a medical treatment or not in order to comply with federal workplace recording laws.

For example, a therapeutic exercise or physical therapy provided on the worksite to address a workplace injury may be considered medical treatment under the Occupational Safety and Health Administration's recordkeeping guidelines. By: Elly McGuinness. By: Jennifer Crump. Dictionary Dictionary Term of the Day. Workplace Testing Terms. Follow Connect with us.