Cross-tolerance

Cross-tolerance

Cross-tolerance refers to a pharmacological phenomenon, in which a patient being treated with a drug exhibits a physiological resistance to that medication as a result of tolerance to a pharmacologically similar drug. In other words, there is a decrease in response to one drug due to exposure to another drug. It is observed in treatment with antivirals, antibiotics, analgesics and many other medications.

Cross-tolerance is particularly frequent amongst users of illicit drugs. For example, users with a high tolerance to the stimulant amphetamine may also exhibit a high tolerance to the structurally similar methamphetamine or other amphetamine-like stimulants. The phenomenon is also observed in cigarette smokers, in whom there is a demonstrably lessened sensitivity to the effects of caffeine. Cross-tolerance is also frequent in response to use of hallucinogens. General tolerance to the effects of tryptamines such as psilocybin, may be dramatic in response to repeated use, and this often translates into a tolerance to effects of other drugs such as Mescaline or DMT. This is also true of benzodiazepines such as Xanax and Klonopin, even opiates as well.


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  • cross-tolerance — /kraws tol euhr euhns, kros /, n. Physiol. the resistance to one or more effects of a substance because of tolerance to a pharmacologically similar substance: a cross tolerance of some alcoholics to anesthetics. [1920 25] * * * …   Universalium

  • cross-tolerance — cross tol·er·ance krȯ stäl( ə) rən(t)s n tolerance or resistance to a drug that develops through continued use of another drug with similar pharmacological action * * * cross tol·er·ance (krosґtol″ər əns) extension of the… …   Medical dictionary

  • cross-tolerance — cross′ tol′erance n. pha resistance or low reaction to the effects of a drug, poison, etc., because of tolerance to a pharmacologically similar substance • Etymology: 1920–25 …   From formal English to slang

  • cross-tolerance — ˈ ̷ ̷| ̷ ̷( ̷ ̷) ̷ ̷ noun Etymology: cross (III) : a tolerance or resistance to the action of a drug brought about by the development of a tolerance to another drug of similar pharmacologic action that has been in continued use …   Useful english dictionary

  • cross-tolerance — noun Date: circa 1923 tolerance or resistance to a drug that develops through continued use of another drug with similar pharmacological action …   New Collegiate Dictionary

  • Cross-presentation — The term cross presentation denotes the ability of certain antigen presenting cells to take up, process and present extracellular antigens with MHC class I molecules to CD8 T cells (cytotoxic T cells). Cross priming describes the stimulation of… …   Wikipedia

  • Cross-reactivity — is the reaction between an antibody and an antigen that differs from the immunogen. It is sometimes also referred to as crossimmunity or cross protective immunity.[1] A few examples of cross reactivity have been confirmed in humans, one of which… …   Wikipedia

  • Cross-resistance — is the tolerance to a usually toxic substance as a result of exposure to a similarly acting substance. It is a phenomenon affecting e.g. pesticides and antibiotics. As an example rifabutin and rifampin cross react in the treatment of tuberculosis …   Wikipedia

  • Tolérance zéro (homonymie) — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. L expression tolérance zéro, ou son équivalent anglais « zero tolerance », peut se rapporter à : une doctrine sociologique qui écarte les… …   Wikipédia en Français

  • tolerance — 1. The ability to endure or be less responsive to a stimulus, especially over a period of continued exposure. 2. The power of resisting the action of a poison or of taking a drug continuously or in large doses without injurious effects. [L.… …   Medical dictionary

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