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1 Feb 2012

Document Summary

Drug tolerance (tolerance) occurs when there is decreased susceptibility (or diminished response) to the effects of a given amount of drug as a result of previous exposure, typically caused by repeated exposures to the drug. -this implies that increasingly larger doses of the drug are required to induce the same behavioral effect. Tachyphylaxis/acute tolerance noticeable decrease in the organism s sensitivity to the drug occurs over a very short period of time. Cross-tolerance development of tolerance to one type of drug results in decreased sensitivity to the effects of another type of drug. There are 3 types of dug tolerance: pharmacokinetic tolerance (metabolic/dispositional tolerance), pharmacodynamic tolerance (functional/nonassociative tolerance), context-specific tolerance (behavioral/learned/associative tolerance) -pharmacokinetic/pharmacodynamic are produced by exposure to high concentrations of a drug and aren t affected by environmental/behavioral manipulations of the organism. -context-specific tolerance is very sensitive to behavioral and environmental manipulations and involves learning and memory.