intro Flashcards
1
Q
what is a drug
A
a chemical compound that may produce psychological, behavioural and physiological effects
2
Q
what is psychoactive effects
A
refers to the alterations in cognitive, motor and behavioural processes
3
Q
what are the most commonly used categorizations of drugs (9)
A
- Alcohol
- caffeine (minor stimulants)
- nicotine
- cannabis
- hallucinogens
- Inhalants
- major stimulants
- sedative-hypnotics
- opiates
4
Q
what are some uses of drugs?
A
- medically prescribed to deal with pain but the same drug can also be abused if it is used to get “high”
5
Q
what is the problem with different methodologies of surveys?
A
it makes it hard to compare results
6
Q
more people need treatment for _____ than anything else combine
A
alcohol
7
Q
__% of Canadians aged 15+ consumed an alcoholic beverage in the past year
__% of Canadians aged 15+ exceed the Low Risk Alcohol Drinking Guidelines for either longterm or short term effect
__% of Canadians aged 15+ identified as current smokers
__% of Canadians aged 15+ have tried e-cigarettes
__% of Canadians aged 15+ have used a cannabis product in the last year
__% of Canadians aged 15+ reported in the past year using one of the following illegal drugs: cocaine, amphetamines, MDMA, hallucinogen, heroin etc.
A
- 77%
- 20%
- 13%
- 13%
- 12%
- 2%
8
Q
how many names does a drug have and what are they?
A
- chemical name: describes the molecule and the location of chemical groups on the molecule
- generic/nonproprietary name: commonly used name for a drug that any company can use
- trade/proprietary name: given by the company and can only be used by that company
- street name: derivative of the trade names, or refer to some physical aspect of the drug or a desired effect
9
Q
what is the general process by which a drug enters and exits the body?
A
- administered and absorbed
- travels around the body via the circulatory sys
- drug reaches the site of action and exerts its effects
- drug is metabolized into an inactive form
- drug and its metabolites exit the body
10
Q
what processes are involved in pharmacokinetics? (5)
A
- administration
- absorption
- distribution
- meatbolism
- elimination
11
Q
the process involved in the interaction of a drug with receptors is known as ____.
A
pharmacodynamics
12
Q
what are the most common ways a drug is taken?
A
- orally (absorption across mucous membranes or skin)
- inhalation/pulmonary
- injection
13
Q
what is the process if a drug is taken orally?
A
- the drugs must pass thro the stomach and small intestines before it reaches the bloodstream
- the stomach is very acidic and most drugs are very alkaline so they get destroyed in the stomach environment (ie. they become ionized and cannot pass out of the bloodstream)
- if the drug makes it to the small intestine it can pass into the bloodstream via simple diffusions bc the small intestine environment is more alkaline
- the drug also passes thro the liver where a majority of the drug is metabolized before it has a chance to exert its effects
14
Q
some facts about drugs that are inhaled? what 2 terms are used for the inhalation of solvents?
A
- most effective way to feel the effects of a drug the fastest
- produce a lot of lung damage
- “huffing” and “bagging”
- when inhaled the drug can reach the brain in 8s which is more effective than if it was taken intravenously
15
Q
what are some facts about the process of injecting drugs intravenously? What does “mainlining” and “skin popping” mean?
A
- drugs taken via injection enter the bloodstream largely dependant on the blood flow in the area of injection
- intravenous injections go straight into the bloodstream so the blood flow isn’t relevant
- Mainlining: intravenous injections in the drug subculture
- skin popping: subcutaneous injections of illicit drugs
16
Q
what 2 factors influence the entry of a drug into the circulatory sys?
A
- Ionization: most drugs are weak acids and bases meaning they get ionized quickly - ionized molecules are not readily absorbed and thus the % of nonionized molecules determines the rate of absorption
- gastric emptying can greatly influence the onset of a drug
- ionized particles are less fat-soluble - Lipid Solubility: important for drugs to exert their effects - lipid-soluble compounds penetrate cell membranes easier than non-lipid soluble compounds
17
Q
how does the brain protect itself from the compounds that it can be impacted by? how is the placenta similar?
A
- blood-brain barrier: not a physical barrier but a barrier in the sense that the permeability in the brain capillaries are very restricted and selective
- the barrier reduces diffusion of water-soluble and ionized molecules but lipid-soluble and unionized particles are fine
- the placenta is similar to the blood-brain barrier so anything a mother takes is passed along to the fetus
18
Q
Receptor binding
A
- drugs exert their effects by interacting with receptors at the target tissue
- a bond forms between the charged groups in the receptor molecule and the oppositely charged groups on the drug
- a drug’s effect is proportional to the fraction of receptors occupied
- binding is reversible
19
Q
agonist
A
a drug that mimics the effect of a neurotransmitter - binds to the receptor and blocks the reuptake of the released neurotransmitter or inhibits the breakdown of the neurotransmitter
- it is possible to reduce the effects of an agonist by using a weaker agonist to occupy the receptor binding spots
20
Q
Antagonists
A
compounds which reduce the effects of a receptor agonist by binding to active receptors but producing no pharmacological action (ie. Naloxone)
21
Q
Dose-response curve (DRC)
A
- drugs produce biological responses that are graded according to the amount administered
- DRC is the most commonly used graphical presentation of drug effects
- y-axis: shows the % of subjects exhibiting the measured effect
- x-axis: shows dose
- DRC allows for potency comparison
- drugs have more than 1 effects so there are multiple DRCs
22
Q
ED50
A
dose of the drug that is effective in producing a response in 50% of participants
23
Q
LD50
A
refers to the dose that kills 50% of participants
24
Q
Therapeutic index
A
for a drug effect is measured by LD50/ED50
- the higher the ration between the 2 the less likely theres a chance that lethal or toxic effecs will occur
25
margin of safety
more conservative measure of a drug's safety and is the ration of the LD1/ED99
- it will always be a smaller number than the therapeutic index bc it is more conservative estimate of the saftey of the drug
26
what is tolerance and how is it represented on the dose-response curve?
- chronic administration of a drug may result in reduced effects
- represented by a shift to the RIGHT of the dose-response curve
- ie. you need to take a larger dose of the drug to feel the same effects
27
what is sensitization and how is it represented on the dose-response curve?
- chronic use of a drug causes its effects to have more of an impact on the user
- represented by a shift to the RIGHT on the dose-response curve
28
what is cross-tolerance?
- tolerance of the effect of one drug produces the tolerance
29
what is cross-sensitization?
to the neural and behavioural effects of the addictive drug
30
does tolerance occur on a drug? What about tolerance and other drugs? the desired or lethal effect?
- tolerance occurs on the EFFECTS of the drug and not the drug itself
- tolerance develops at different rates for different drugs effects
- tolerance occurs on the desired effects more than the lethal ones
31
what happens to the therapeutic index and what is the problem with varying purity of a drug?
- the therapeutic index is separate from the ED50 and it would decrease and the user would be exposed to adverse effects
- since street drugs vary in purity someone with a high tolerance they may not know that the purity of the drug increased so it could subject them to an overdose
32
what is physical dependence and how is it related to tolerance? What type of reinforcement is this?
- tolerance is related to the DEVELOPMENT of physical dependence
- defined as when a chronic user experiences a withdrawal syndrome upon cessation of administration
(ie. headache if you don't drink coffee)
- NEGATIVE reinforcement
33
why isn't the word "addiction" used in professional practice? What word is used instead?
- Addiction is not used because of its uncertain definition and its potentially negative connotation
- "substance use" disorder is considered more neutral term and is a diagnostic category in the DSM
34
what are the 9 classes of drugs that are classified for substance use disorder that is recognized by the DSM?
1. Alcohol
2. Cannabis
3. Hallucinogens
4. inhalants
5. Opioids
6. sedative-hypnotics and anxiolytics
7. stimulants
8. tobacco
9. other (ie. anabolic steroids)
35
what is the essential feature of substance use disorder? what is an important characteristic of substance use disorder - what is the behavioural effect on the brain with these changes?
- a cluster of cognitive, behavioural, and physiological symptoms indicating that the person continues to use the substance despite significant substance-related problems
- underlying change in brain circuits that may persist beyond detoxification
- behavioural effect on the brain with these changes are exhibited in repeated relapse and intense drug craving when the individual is exposed to drug stimuli
36
American Psychiatric Association - what are the 3 levels they recognize according to the 4 categories?
1. Impaired control
- may take the drug longer than they need
- may spend a lot of time trying to get the drug, use the drug and recover from the effects of the drug
- may express a desire to cut down but has had many unsuccessful attempts
- Cravings (ask if there has been a time where the craving was so intense that's all they could think of)
2. Social Impairment
- failure to fulfil major role obligations (ie. work, school etc.)
- continue using the drug knowing the social impairments
3. Risky Use
- the individual continues using the drug despite knowing the persistent or recurrent physical or psychological problems associated with it
4. Pharmacological criteria
- tolerance
- withdrawal symptoms
* * don't need tolerance or withdrawal symptoms for a diagnosis
* * each category is weighted equally
LEVELS:
Mild: 2-3
Moderate: 4-5
Severe: 6+
37
what's the difference between Substance-induced disorders and Substance Use disorders?
- SIDs is a reversible substance-specific syndrome that is causing some level of problem and is due to recent ingestion of a substance (it includes 10 classes of drugs - the same 9 as SUDS and caffeine)
- includes intoxication, and withdrawal
* caffeine is not recognized in SUDs but is recognized in SIDs)
38
What are the several routes to drug elimination?
- skin
- lungs
- kidneys
- small percentage exits by body sweat
- some volatile gases and alcohol are exhaled
39
What is the most important route of elimination?
- via urine, after it has been metabolized by the liver
40
why is the liver important for breaking down drugs? what is an enzymatic breakdown and why is it important?
- a major site of enzymatic breakdown of drugs
- enzymatic breakdown results in metabolites that are less lipid-soluble, larger and carry a greater charge and are inactive or less active than the original compound
- this is important bc it is harder for the molecules to be reabsorbed by the kidneys
41
what role does renal absorption play? Weak acids and weak bases?
- pH-dependent
- weak acids are excreted more readily when the tubular urine is alkaline this is bc they become more ionized and "trapped" in the tubular urine
- weak bases are excreted more if the urine is more acidic
42
what is the relation between reabsorption and pH?
- used in the treatment of drug toxicity
- sodium acetate is a urinary alkalizer
- sodium biphosphate is a urinary acidifier
- slow process and not useful in acute overdose
43
Elimination half-life - what is it and why is it important? examples? what is the average half-life for drugs to be 98.4% out of the body?
- refers to the time needed for half of a drug dose to be eliminated from the body
- important in understanding the duration of the effect of the drug and which drug to use for certain medical treatments
- benzodiazepine would be a good sleeping agent bc of its short half-life and one with a long half-life would be good for something like anxiety
- takes about 6 half-lives for most of the drug to be eliminated and for the person to be considered drug-free
44
how do drugs exert their action?
- affect neurotransmitters
45
autoreceptors and their role?
- these are receptors on the pre-synaptic neuron that act as negative feedback for the release of a neurotransmitter
46
what is the general model of the synthesis and breakdown of a neurotransmitter substance (6)
1. Precursor substances (ie. amino acids from diet) are the basic building blocks of neurotransmitters
2. Synthesizing agents are needed to build a neurotransmitter and they act as the rate-limiting step
3. needs to be transported to the presynaptic terminal
4. neurotransmitter is released
5. binds to the postsynaptic receptor
6. neurotransmitter becomes unbound so 3 things can happen (a) bind again and produce additional action (b) attach to a transporter protein to be taken back into the pre-synaptic element to be used again or (c) attach to proteins that catabolize or break down the neurotransmitter
