drug tolerance - definition of drug tolerance in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia.

tolerance /tol·er·ance/ (tol´er-ans)

1. diminution of response to a stimulus after prolonged exposure.

2. the ability to endure unusually large doses of a poison or toxin.

drug tolerance decrease in susceptibility to the effects of a drug due to its continued administration.

immunologic tolerance the development of specific nonreactivity of lymphoid tissues to a particular antigen capable under other conditions of inducing immunity, resulting from previous contact with the antigen and having no effect on the response to non–cross-reacting antigens.

impaired glucose tolerance (IGT) a term denoting values of fasting plasma glucose or results of an oral glucose tolerance test that are abnormal but not high enough to be diagnostic of diabetes mellitus.

drug tolerance,

a condition of cellular adaptation to a pharmacologically active substance so that increasingly larger doses are required to produce the same physiologic or psychologic effect obtained earlier with smaller doses. Also called metabolic tolerance . See also tachyphylaxis.

drug(s),

n a substance used in the prevention, cure, or alleviation of disease or pain or as an aid in some diagnostic procedures.

drug absorption,

n See absorption, drug.

drug abuse,

n an excessive or improper use of drugs, especially through self-administration for nonmedical purposes. This term has increased significance because of the enactment of the Comprehensive Drug Abuse Prevention and Control Act of 1970, which replaces the Harrison Narcotic Act. See also substance abuse.

drug combinations,

n.pl the use of drugs together to enhance the properties of both to the benefit of the patient.

drug dependence,

n a physical or psychologic state in which a person displays withdrawal symptoms if drug use is halted suddenly; can lead to addiction.

Drug Enforcement Administration (DEA),

n.pr the federal agency charged with monitoring use and abuse of narcotics. It provides the drug schedules used to determine the addiction potential of dental drugs.

drug hypersensitivity,

n an allergic reaction that occurs after exposure to a suspect medication. It may manifest with a fever or rash and in severe cases, organ damage or death. It is classified as (1) immediate or occurring rapidly after exposure, or (2) delayed or occurring several days after exposure.

drug idiosyncrasy

n an adverse drug reaction that occurs in a small number of persons and presents no correlation to dosage or means of therapy.

drug interaction,

n a modification of the effect of a drug when administered with another drug. The effect may be an increase or a decrease in the action of either substance, or it may be an adverse effect that is not normally associated with either drug.

drug resistance,

n the capacity of a microorganism to build a tolerance to a drug.

drug stability,

n the length of time a drug retains its properties without loss of potency; usually referred to as shelf life.

drug therapy,

n the use of a drug in the treatment of a patient with a specific disease or illness.

drug tolerance,

n the body's ability to increasingly withstand the effects of the substance being used, thereby requiring larger quantities of said substance in order to bring about the desired result.

drug toxicity,

n the critical or lethal reaction to an erroneous dosage of a medication. Drug toxicity may occur due to human error or intentional overdose in the case of suicide or homicide.

drugs, antibiotic,

n.pl the chemical compounds obtained from certain living cells of lower plant forms, such as bacteria, yeasts, and molds, and from synthesis. They are antagonistic to certain pathogenic organisms and have a lethal effect on them.

drugs, antimicrobial,

n.pl the drugs, mainly penicillin and its derivatives, used to combat viral, fungal, and parasitic infections.

drugs, antiseptic,

n.pl the chemical compounds used to reduce the number of microorganisms in the oral cavity.

drugs, autonomic,

n.pl the drugs that mimic or block the effects of stimulation of the autonomic nervous system.

drugs, desensitizing,

n.pl the agents used to diminish or eliminate sensitivity of teeth, especially the dentin, to physical, chemical, thermal, or other irritants (e.g., strontium chloride, silver ammoniacal] or potassium nitrate, sodium fluoride, formalin, zinc chloride). See hypersensitivity, dentin.

drugs, endodontic,

n.pl the drugs used in treating the dental pulp and dental periapical tissues.

drugs, nonofficial,

n.pl the drugs that are not listed in the United States Pharmacopeia (U.S.P.) or the National Formulary (N.F.).

drugs, official,

n.pl the drugs listed in the U.S.P. or N.F.

drugs, officinal

n.pl drugs that may be purchased without a prescription. More commonly called
over-the-counter (OTC) drugs.

drugs, over-the-counter (OTC),

n.pl the drugs that may be purchased without a prescription. Sometimes called nonlegend drugs because the label does not bear the prescription legend required on all drugs that may be dispensed only on prescription.

drugs, parasympathetic

n.pl the belladonna alkaloids that inhibit glandular secretions of the nose, oral cavity, pharynx, and bronchi. This is the main reason for using atropine and scopolamine for preanesthetic or preprocedural medication.

drugs, parasympatholytic

(per´

sim´p

thōlit´ik),
n.pl the drugs that block nerve impulses passing from parasympathetic nerve fibers to postganglionic neuroeffectors.

drugs, parasympathomimetic

(per´

sim´p

thōmimet´ik),
n.pl the drugs that have an effect similar to that produced when the parasympathetic nerves are stimulated.

drugs, proprietary

(pr

prī´iter´ē),
n.pl the drugs that are patented or controlled by a private organization or manufacturer.

drugs, psychoactive

n.pl the drugs or other agents that have the capacity to become habit forming because of their influence on mood, behavior, or conscious thought; may be therapeutic or recreational.

drugs, sympathetic,

n.pl the agents that imitate the sympathetic autonomic nervous system actions. They usually cause raised levels of alertness and anxiety. Various types are used in dentistry as vasoconstricters in conjunction with local anesthetics. See also adrenergic agents.

tolerance

the ability to endure without effect or injury.

drug tolerance

1. decreased susceptibility to the effects of a drug due to its continued administration.

2. the maximum permissible level of a drug in or on animal feed or food at any particular time relative to slaughter.

high-dose tolerance

in immunology, that induced by the intravenous administration of high doses of aqueous proteins.

immunological tolerance

specific nonreactivity of the immune system to a particular antigen, which is capable under other conditions of inducing an immune response. There is, under normal circumstances, tolerance to self-antigens; identical (monozygotic) twins and dizygotic cattle or sheep twins where there has been placental fusion and exchange of bone marrow stem cells are also tolerant of each other's tissues. Allophenic mice, that is mice produced by fusion of blastocysts from different mice are also tolerant of both 'parents'. The administration of antigens either at high or low dose and infection with certain viruses during critical early stages of immunological development may also induce tolerance.

tolerance level

the concentration of a drug or chemical permitted by law to be present in human food.

tolerance limits

the numerical limits within which a previously identified proportion of values of a variable, or observations in a population, can be expected to occur.

low-dose tolerance

that induced by repeated administration of low doses of the antigen.

oral tolerance

that induced by oral administration of the antigen.

self-tolerance

the non-reactivity of the immune system to self-antigens.

tolerance test

see tolerance test.

zero tolerance

when no detectable amount of a chemical substance is permitted in human food.

drug tolerance

Psychiatry Repeated use of some substance or drug, often narcotics, so that ever larger doses are required to produce the same physiologic and/or psychologic effect obtained previously by a smaller dose.