Mod 5: Drugs & Addiction Flashcards
Which system do psychoactive drugs act on?
- The nervous system
This causes changes in conscious experience and behavior.
What do psychoactive drugs consist of?
- illicit drugs
- legal drugs
- prescription drugs.
What are the characteristics of a drug?
- Exogenous chemical
- Not necessary for normal cellular functioning
- Significantly alters the functions
- Has effects in relatively small doses
What drugs affect the conscious experience?
- Alcohol
- Marijuana
- Stimulants
- Caffeine
- Cocaine
- Nicotine
- Methamphetamine & amphetamine
- Hallucinogens
- LSD
- Ecstasy.
What are the categories of drugs?
- Drugs that relieve symptoms
- Drugs that affect the conscious experience
What drugs make up those that relieve symptoms?
- Antipsychotic
- Antidepressants
- Anxiolytics
- Opiates.
Drugs are considered to be exogenous, therefore, before entering the body there must be…?
A route of administration
1. Inhalation (lungs/blood/brain)
2. Snorting (nasal passage/blood/brain)
3. Swallowing (is slower/ the body is able to metabolize it)
4. I.V.- Straight to blood/to the brain (most brain-direct route)
Once the drug is in the body, how does it get access to the brain?
It must go through the B.B.B
Then it alters transmission @ synapses
What is an antagonist?
- Blocks receptors
- Blocks terminal
Drug the blocks or decreases the effectiveness of a NT
What is an agonist?
A drug that mimics or increases the effectiveness of a NT.
- Activates receptor
- Blocks reuptake
- Blocks enzymatic degradation.
What system do psychotropic drugs interact with to alter neural transmission?
With the components within the NT systems.
What are examples of agonists that block reuptake?
Cocaine
* Cocaine blocks the dopamine transporter
What are some drugs that activate the receptor?
- Nicotine
* Activates ACh receptor
- Xanax
- Activates GABA receptors
An antagonist blocks the receptor. what drug performs this action?
Antipsychotics
* Block dopamine receptors
Explain what drug effects depend on.
The effect depends on the dose of the drug (aka. dose-response curve)
How does repeated drug administration alter the effects of the drug?
It alters the drug response curve, which influences the effect of the drug.
Explain drug tolerance and its effect on the drug response curve.
Drug tolerance is decreased sensitivity due to high exposure to the drug.
*The curve shifts to the right
* If there is no increase in the dose, then the drug effect decreases.
* In order for there to be an effect, more of the drug is needed.
How are drug tolerance & drug sensitization different from each other?
W/ tolerance your body becomes desensitized, whereas w/ sensitization your body becomes more sensitive to the effects w/o there being any changes in the drug dose.
!!! NOT AS COMMON !!!
Repeated cocaine exposure has an effect on what pathway?
Has increased activity in the reinforcement pathway
Explain the consequences that could stem from cross-tolerance.
Exposure to one drug can produce tolerance for other similar drugs.
Provide an example of two drugs that could lead to cross-intolerance.
Alcohol & benzodiazepine (anti-depresso)
- Both are GABA receptors antagonist
How does metabolic intolerance affect the site of action?
The full effect of the drug isn’t getting to the site of action
What is functional tolerance?
Decreased responsiveness at the site of action
Explain how the site of action becomes less responsive during functional tolerance.
- Fewer receptors
- Decreased efficiency of binding at receptors
- Receptors become less responsive.
Which type of drug shows functional tolerance?
Psychoactive drugs
* As the brain compensates for changes due to drug
What are the different types of antipsychotics?
2nd gen antipsychotics
What are the characteristics of 1st gen antipsychotics?
- Relieve + symptoms of schizophrenia
- Antagonist of dopamine receptors
What are the characteristics of 2nd gen antipsychotics?
- Helps in receiving - symptoms
- Has other actions other than being a dopamine antagonist
- Blocks certain dopamine receptors
Antidepressants can act to increase what?
Increased synaptic transmission
What’s the function of tricyclic antidepressants?
- Block reuptake of transmitter molecules into the presynaptic terminal
What are examples of antidepressants?
- Tricyclic antidepressants
- Monoamine Oxidase Inhibitors (MAO)
- Selective serotonin reuptake inhibitors (S.S.R.Is)
What are the different anxiolytics?
Benzodiazepines
Explain how benzodiazepines help with anxiety.
- The reduce the excitability of neurons
- Bind to specific sites on GABA receptors, enhance the activity of GABA to produce larger IPSPs
What is a common benzodiazepine?
Xanax
What are some recognizable opiates?
- Heroin, methadone
- Narcotics (pain relievers)
What do opiates bind to?
Bind to opioid receptors concentrated in various regions of the brain.
Opiates are agonists for…?
Mu opioid receptors
*Inhibition of neuron
Why are the effects of opioid drugs widespread?
Mu-opioid receptors are in most regions of the brain so its effects are felt across the brain.
What drug is methadone used to reverse?
Combats heroin addiction
How does methadone function?
- Binds to the same receptor as an agonist (heroin & morphine)
- Has a gradual effect
(!! no crash = moderate withdrawal !!)
What are the possible cons of methadone?
- Still highly addictive
- Less pleasurable, less dangerous.
Why is Naloxone (Narcan) used for overdoses?
- Opioid receptor antagonist
- It reverses opioid overdose
Opioids that Narcan reverses?
- Morphine
- Heroin
- Fentanyl
- Methadone
What are the internal factors that increase the risk of drug addiction?
- Genetics
- Sex
- Poor emotional regulation
What external factors could increase the risk of drug addiction?
- Context of exposure (exposure @ home/hospital)
- Living situation (high drug rate neighborhood)
- Poor family life
Explain the “moral model” theory of addiction.
- Weakness of character & lack of self-control
CONS: punishments & scolding don’t really work
Ex: DARE/ “Just say no”
Explain the “disease model” theory of addiction.
- People need medical treatment rather than being punished
CONS: no disease-like physical abnormality has been identified that cause addiction.
Ex: The War on Drugs
What is the positive reward model?
Drugs are reinforcing
