Tolerance Flashcards
what is tolerance
repeated exposure to the same dose of a drug results in a lesser effect
What is cross tolerance
development of tolerance to one drug results in a decreased sensitivity to another type of drug
What are the types of drug tolerance
Pharmacokinetic (metabolic) tolerance
Pharmacodynamic (physiological) tolerance
Context-specific tolerance
what is pharmacokinetic tolerance
involves adaptions in the way the body acts on the drug ex. liver produces more of a certain enzyme to combat drug use
what is unique about metabolic tolerance
ALL of a drug’s effects will develop tolerance because it is due to overall decrease in the concentration of the drug
What is pharmacodynamic tolerance
involves adaptions in the way individual neurons respond to the drug; viewed as the brain’s attempt to maintain its level of functioning within normal limits
how does pharmacodynamic tolerance counteract drugs that mimic or amplify the actions of a neurotransmitter
down-regulation and desensitization
how does pharmacodynamic tolerance counteract drugs that act as antagonists or dampen the actions of neurotransmitters
up-regulation and sensitization
What is context specific/behavioral tolerance
when a drug is taken in one environment and displays tolerance within that environment but loses tolerance when taken in another environment
how is classical conditioning related to drug use
The drug paraphernalia used to get high becomes the conditioned stimulus after repeated drug use; eventually just the drug paraphernalia will elicit a small euphoric response
how does tolerance affect the safety margin
as tolerance increases the safety margin of a drug decreases as the dose gets closer to a lethal amount
what is sensitization
increased response to same dose with repeated exposure or less drug needed to achieve same effect
How is homeostasis related to drug use
the body will implement changes that are opposite to those produced by the drug
what is physical dependence
defined by the occurrence of a withdrawal syndrome
what is withdrawal syndrome
set of defined symptoms associated with a decrease in the blood levels of a particular drug
what causes withdrawal symptoms
due to changes in the nervous system that are in place in response to the chronic presence of the drug; when the drug is removed, the compensatory mechanisms are exposed and an imbalance results
How does withdrawal syndrome vary from drug to drug
the duration and intensity of withdrawal syndrome is highly correlated with the duration and intensity of drug’s direct effects
what is the risk of abstinence
loss of tolerance during period of abstinence causes an increased risk of overdose
what is PAWS
post acute withdrawal syndrome is withdrawal symptoms after the immediate withdrawal period
