Lecture 12. Drug Use, Drug Addiction, and the Brain's Reward Circuits Flashcards
drugs that influence subjective experience and behavior by acting on the nervous system.
Psychoactive drugs
route of administration influences the rate at which and the degree to which the drug reaches its sites of action
Drug administration
4 Drug Administration and Absorption
- Oral Ingestion
- Injection
- Inhalation
- Absorption through mucous membranes
the ___ ___ is the preferred route of administration for many drugs
oral route
two main advantages of the oral route:
- easy
- relatively safe
common in medical practice because its effects of are strong, fast, and predictable
injection
Types of Injection
- Subcutaneously (SC)
- Intramuscularly (IM)
- Intravenously (IV)
type of injection that is into the fatty tissue just beneath the skin
Subcutaneously (SC)
into the large muscles
Intramuscularly (IM)
directly into veins at points where they just run just beneath the skin
Intravenously (IV)
Some drugs can be absorbed into the bloodstream through the rich network of capillaries in the lungs.
Inhalation
Some drugs can be administered through the mucous membranes of the nose, mouth, and rectum
absorption through mucus membranes
Once a drug enters the bloodstream, it is carried
to the blood vessels of the central nervous system
Drug Penetration of the Central
Nervous System
stimulate the conversion of active drugs to non-active forms
liver enzyme
a state of decreased sensitivity to a drug that develops as a result of exposure to it
Drug Tolerance
One drug can produce tolerance to other drugs
that act by the same mechanism
cross tolerance
Increasing sensitivity to a drug
drug sensitization
Two categories of changes underlie drug tolerance
- Metabolic tolerance
- Functional tolerance
drug tolerance that results from changes that reduce the reactivity of the sites of action to the drug
Functional tolerance
drug tolerance that results from changes that reduce the amount of the drug getting to its sites of action
Metabolic tolerance
sudden elimination that can trigger an adverse physiological reaction after significant amounts of a drug have been in the body for a period of time
withdrawal syndrome
Individuals who suffer withdrawal reactions when
they stop taking a drug are said to be ___ ____ on that drug
physically dependent
habitual drug users who continue to use a drug
despite its adverse effects on their health and social life, and despite their repeated efforts to
stop using it
Drug Addicted Individuals
2 Role of Learning in Drug Tolerance
- Contingent Drug Tolerance
- Conditioned Drug Tolerance
demonstrations that tolerance develops only to drug effects that are actually experienced
Contingent Drug Tolerance
two groups of subjects receive the same series of drug injections and the same series of repeated tests, but the subjects in one group receive the drug before each test of the series and those in the other group receive the drug after each test of the series
Before-and-after design
demonstrations that tolerance effects are maximally expressed only when a drug is administered in the same situation in which it has previously been administered
Conditioned Drug Tolerance
increasingly counteract the unconditional effects of the drug and produce situationally specific tolerance
Conditioned compensatory responses
Most demonstrations of conditioned drug tolerance have employed ___ ____ as the conditional stimuli.
exteroceptive stimuli
internal, private stimuli
interoceptive stimuli
Five Commonly Used Drugs
- Nicotine
- Alcohol
- Marijuana
- Cocaine and Other Stimulants
- The Opioids: Heroin and Morphine
major psychoactive ingredient of tobacco
Nicotine
NIcotine is most commonly administered through ___
inhalation
Nicotine is classified as both a ____ and a ___
stimulant and depressant
Two common methods of nicotine inhalation
- smoking
- vaping
inhaling a vapor that contains
nicotine
vaping