test 2 Flashcards
Properties of drugs and models of dependence
what are pharmacodynamics?
they physiological actions of drugs
what are pharmacokinetics?
how drugs move through the body
what are the 4 stages of pharmacokinetics?
- absorption
- distribution
- biotransformation
- elimination
what are the routes of administration in order of fastest acting to slowest acting?
-intravenous
-inhalation
-insufflation
-intramuscular injection
-subcutaneous injection
-oral administration
what are the benefits of intravenous drug absorption? what are the risks?
-high concentrations can be delivered and there is no absorption limit
-veins may become damaged over time if the same injection site is used repeatedly and blood-borne diseases can spread
what happens in inhalation? what are the effects? what are the risks?
-the drug moves from the lungs into the bloodstream through the capillary walls
-rapid onset effects
-control of dose is difficult and lung toxicity
what happens in insufflation? how fast does it happen? what are the risks?
-absorption through the mucous membranes into the bloodstream
-within minutes
-nasal necrosis and hepatitis C (from sharing insufflation devices)
what is intramuscular injection? what are the benefits how is it useful?
-in a muscle
-absorption is more rapid due to greater blood supply in muscles
-useful with noncompliant patients
what is subcutaneous injection? what is the risk?
-under the skin
-can cause necrosis if the same injection site is used
how fast is oral administration?
relatively slow, 15-60 minutes
what must a drug go through when taken through oral administration?
-withstand digestive acid
-pass through the cells lining the gastrointestinal tract into the bloodstream (mostly in the small intestine)
-pass through the liver where they may be metabolized
why is oral administration used as the method for most over the counter and prescription medications?
it is the safest
-the stomach can be pumped in case of overdose
-some drug is broken down before it reaches the brain and the potential negative outcomes are reduced
what is distribution?
passage of the drug from the bloodstream to sites of action in the body
what is absorption?
drug being absorbed into the bloodstream and drug administration
what is bioavailibility?
the ability of a drug to reach a site of action (typically in the brain)
what is the blood-brain barrier?
barrier that surrounds the blood capillaries and vessels in the brain and prevents substances in blood from entering the brain
what is elimination?
process by which drug leaves the body; the goal is to produce a steady state of drug effects
what does the elimination rate determine? what is a half-life?
-how long the effects will last
-duration of time necessary for the body to eliminate half of the drug
how do drugs alter the availability of neurotransmitters during synthesis? what is an example?
-create the neurotransmitter molecule
-LDOPA for Parkinsons disease
how can drug affect neurotransmitter availability during storage in vesicles? what is an example?
- immediate release of neurotransmitters instead of storage in vesicles
-amphetamines, MDMA
what are examples of drugs that affect the availability of neurotransmitters during reuptake?
SSRIs and cocaine
how can drugs affect neurotransmitter availability during metabolism? what is an example?
-increase or decrease the enzyme that metabolize the neurotransmitter
-MAOI (monoamine oxidase inhibitor) antidepressants and acetylcholinesterase inhibitor for Alzheimer’s disease
what does an agonist do? what is an example?
-fully activates a receptor by sitting in and binding to a receptor site
-opiates (bind to endorphin receptors)
what does an antagonist do? what is an example?
-fails to activate receptor but bind to receptor site
- botox (blocks acetylcholine), naloxone (blocks opiate receptor sites and can displace opiate already bound to the receptor site), antipsychotics (block dopamine)
what is a positive modulator? what does it allow for? what is an example?
-drug that increases binding affinity and receptor efficacy
- allows for natural neurotransmitters to bind better to receptor sites
- benzodiazepines, alcohol
what is a negative modulator? what does it do?
- drug that decreases binding affinity and receptor efficacy
-decreases the effectiveness of neurotransmitters
what is binding affinity?
drug’s strength of binding to a receptor
what is receptor efficacy?
drug’s ability to alter the activity of the receptor
what is pharmacokinetic (drug dispositional) tolerance? what is it typically due to?
-reduction in amount of drug reaching site of action
-increased rate of catabolism or enzyme activity
what is pharmacodynamic tolerance? what happens when drug use is stopped?
-sensitivity of neurons may change after repeated use
-CNS experiences improper balance of neurotransmitters and withdrawal symptoms occur
what is behavioral tolerance?
same biochemical effect but reduced behavioral effect as drug user learns to compensate
what is cross tolerance?
tolerance for other drugs with similar mechanisms of action
what happens in physical dependence?
-withdrawal symptoms which are a consistent set of symptoms that appear after discontinuing use of a drug; they are typically the opposite of the drug effects
-the body’s normal regulatory mechanisms compensate for the presence of a drug and when use stops, there is a physiological imbalance
what is psychological dependence indicated by?
-high frequency of drug use
- craving for the drug
-tendency to relapse after stopping use
what is positive reinforcement?
behavior increases when stimulus is present
what is positive punishment?
behavior decreases when stimulus is present
what is negative reinforcement?
behavior increases when a stimulus is removed
what is negative punishment?
behavior decreases when a stimulus is removed
what is incentive salience? what is the incentive salience model?
- stimulus is easily recognized and payed attention to and stimulus motivates behavior that is directed towards it
-shift from liking to wanting that explains why dependent users may want a drug more while liking the drug less; in the model, stimuli associated with drug use command attention and elicit a motivational state toward pursuing the drug
what are the two key structures in reward circuitry?
nucleus accumbens and the ventral tegmental area (VTA)
what does the VTA do?
releases dopamine int the nucleus accumbens
how is GABA related to reward circuitry?
inhibits activity of dopamine (increases in GABA decreases the release of dopamine)
how is the amygdala changed by chronic drug use?
-associates stimuli present during drug use with reinforcing effects of the drug
-elicits withdrawal symptoms and negative emotional state when drug is absent through connections with the hypothalamus and medulla
how is the hippocampus changed by chronic drug use?
associates contextual cues with drug taking
how is the basal ganglia (dorsolateral striatum) changed by chronic drug use?
-procedural memory
-ritualistic drug use behavior (behaviors that become automatic once learned)
what is relapse?
return to a chronic drug use state that meets the clinical features of dependence
what are the categories of remission? Define each.
-early remission- 3-12 months of no symptoms meeting dependence criteria
-sustained full remission- no symptoms of dependence for 12+ months
-maintenance- no symptoms while participating in treatment
- controlled environment- living in an environment where drugs are unavailable
what was the purpose of the Harrison act of 1914? what other legislation did it inspire?
-required those who “produce, import, manufacture, compound, deal in, dispense, or give away” certain drugs to register and pay a special tax; initially it just controlled opiates and cocaine
- Marijuana tax act 1937 and drug abuse control act amendment 1965
what is the criteria for a schedule I drug? give examples.
- high potential for abuse, no accepted medical use, lack of accepted safety
- heroin, MDMA, LSD
what is the criteria for a schedule II drug? give examples.
-high potential for abuse, currently accepted medical use, abuse may lead to severe dependence
-cocaine, meth, PCP
what is the criteria for a schedule III drug? give examples.
-potential for abuse less than I and II, currently accepted medical use, abuse may lead to moderate physical dependence or high psychological dependence
-anabolic steroids, barbiturates, dronabinol
what is the criteria for a schedule IV drug? give examples.
-low potential for abuse relative to III, currently accepted medical use, abuse may lead to limited physical or psychological dependence relative to III
-benzodiazepines
what is the criteria for a schedule V drug? give examples.
-low potential for abuse relative to IV, currently accepted medical use, abuse may lead to limited physical or psychological dependence relative to IV
-mixture with small amounts of codeine or opium
what is contingency management? what does it assume?
-individuals receive rewards for providing drug-free urine samples
-drugs can function as reinforcers and long-term change requires finding competing reinforcers so providing incentives for abstinence often results in reduction in drug use
what is cognitive behavioral therapy?
-an approach that combines cognitive therapy techniques with behavioral skill training
-individuals learn to identify and reduce urges to use
-identify and change behaviors that could lead to relapse-shown more effective than most therapies
what is harm reduction?
public health policies or intervention programs designed to reduce the harmful consequences associated with substance use and high-risk activities
what is a compensatory response?
a response that is counter to the primary process
what is an unconditioned stimulus (US)?
stimulus that elicits a reflex response
what is an unconditioned response (UR)?
a reflex response elicited by an unconditioned stimulus
what is a neutral stimulus (NR)?
one that does not elicit a reflex or response
what is a conditioned stimulus (CS)?
stimulus that elicits a conditioned response
what is a conditioned response (CR)?
response elicited by a conditioned stimulus
how does opponent-process theory account for tolerance?
having a stronger or higher opponent process makes it so more of the drug is needed to counter the opponent process and receive the reinforcing effects of the drug
how does the opponent-process theory account for withdrawal?
with repeated presentations of the drug, the opponent process increases in strength and duration, so when the drug is removed the opponent process are more extreme causing withdrawal symptoms
what is self-administration?
a common animal model used to assess the dependence liability of a drug
what scale of reinforcement does self-administration use?
progressive-ratio scale
what is a break point?
maximum amount of response effort the rat will devote to receive the reinforcer
what are the steps of reinstatement?
- rat self-administers drug
- extinction where the drug is removed
- reinstatement where the rat goes back to the drug
what is reinstatement?
the animal model of relapse
what can be used to trigger reinstatement?
-shock that stresses the rat out
-provide a cue that was previously associated with drug use
-give the rat a small dose of the same drug or a similar drug as the one used in self-administration
according to the DSM-V, what is substance use disorder?
a problematic pattern of substance use leading to clinically significant impairment or distress, as manifested by at least two symptoms occurring within a 12-month period
what are the categories for substance use disorder?
-mild- 2-3 symptoms
-moderate- 4-5 symptoms
- severe- 6+ symptoms
how many of the symptoms in the DSM-V describe psychological behaviors?
9/11
