Opiods Flashcards
*Explain the etiology of the current opioid epidemic
Doctors are prescribing 4x as many opiods (240 million prescriptions each year) but there is no change in reported pain
started with: oxycontin in 1996:
Heralded as a way for patients (with cancer) to treat chronic pain and sleep through the night;
Purdue pharmacy lead a HUGE marketing campagin that lead to a flooding of the market
*Describe addiction in lay language
Loss of control over drug use:
USE OF DRUGS DESPITE NEGATIVE CONSEQUENCES. CHRONIC AND RELAPSING
Typically begins in adolescence
primary disease, not secondary to any other illness (a disease of its own)
its chronic, disease of the brain’s reward system, where addicts are really motivated to take drugs and really not motivated to do anything else
ITS A DISEASE OF MEMORY! ITS A LEARNED DISEASE- NOT JUST THE DRUG BUT ITS HOW YOU LEARN TO USE THEM, AND THAT INVOLVES ALL THE UNDERLYING CIRCUITRY IN OUR BRAINS
*List the risk factors for addiction
environmental factors of addiction;
early abuse and neglect in a child can epiginetically alter the density of receptors in the brain (i.e. seratonin receptors, leading to depression) and depression is a risk factor for drug use
these environmental factors change the risk habit
HOW THE ENVIRONMENT CAN EFFECT DRUG USE:
BEING SUBORDINATE IS A RISK FACTOR FOR COCAINE USE (MONKEY EXPERIMENT)
You can choose if you take a drug (the first time) but you can’t choose how you will physiologically respond to the drug and react
*Distinguish tolerance, physical dependence & psychological dependence from each other
take drug:
activates reward sytem in brain (ventral tegmental area, to nucleus accumbens, to prefrontal cortex- limbic part of the basal ganglia)
Also take drugs because they’re soothing, especially antidepressants, take away anxiety, pain
After taking for a while, drugs can remove symptoms of withdrawl so they start taking drugs just so they aren’t feeling bad
Then, the brain starts to physically change as a result
*Diagram the neural circuit that underlies addiction
The release of dopamine in the nucleus accumbens is the key event mediating reward, and comparing food to amphetamine, the increase in dopamine release in the nucleus accumbens is 1000% higher than the increase when presented with food
*All drugs of abuse act on VTA-Nucleus Accumbens circuit except hallucinogens
*Describe the role of the physician in detecting & treating drug use
25% of patients will have an alcohol problem (20% at risk, and 5% dependent); 10% of colleagues will have a problem;
More drug overdoses (usually combined with other drugs or alcohol) than cars guns, or falling)
when the overprescription epidemic became clear,
the prescriptions of oxycontin started leveling off, and there was a huge increase in illeagal opiods like fentanyl, or opiods shipped over from china, etc)
CHARACTERISTICS OF ADDICTION
Genes and environment; 60% of risk for addiction is genetic (determined by twin studies, etc), there’s no GENE for addiction, but there are drugs that may influence the susceptibility
FAS
Fetal alcohol spectrum: fetal alcohol syndrome is the single most preventable common cause of mental retardation
DA receptor density affects drug liking:
those in PET scanner who have low densities of DA receptors are more likely to enjoy stimulants than those who have high densities; so, if you come into the world with a genetic alteration that gives you fewer DA receptors, you’re more likely to like stimulants, and moer likely to use them repeatedly
(first time is always involuntary)
monkey experiment:
sub/dom monkey, after socializing, the dom had more levels of D2 receptors, sub had less, then given coke, the dom took less, and the sub took more
Tolerance:
2 ways, pharmacokinetic: body gets better at getting rid of drug; pharmacodynamic describes cellular adaptation in which cells get use to having the stimulant around-so it’s no as effective
Tolerance: in a pet scan, you can see how:
drugs of abuse decreases the density of D2 dopamine receptors in the striatum after prolonged drug use
the reward system is the release of dopamine from the nucleus accumbens, and there aren’t enough receptors there, even if you release dopamine, it’s not going to have the same effect
explain tolerance:
with repeated drug use, the density of D2 dopamine receptors in the brain GOES DOWN
Measuring Physical Dependence:
no way to measure, you can only take the drug away and measure the withdrawl symptoms
Important: tolerance and physical dependence are NOT ADDICTION, addicts can maintain addiction
