Psychoactive Drugs Exam 1
cerbral cortex
Functions: Thought Voluntary movement Language Reasoning Perception FRONTAL LOBE: Higher order thinking Planning Inhibiting impulses Alcohol reduces frontal lobe response
Adderall
amphetamine/dextroamphetamine
lipophilic
Having an affinity for or an attraction to fat and oils (oil-loving).
Homeostasis
Homeostasis is the basis for withdrawal and tolerance Any self regulating process by which biological systems tend to maintain stability while adjusting to conditions that are optimal for survival In response to chronic alcohol use, liver creates more enzymes that metabolize alcohol. Leads to more tolerance.
Bioavailability
How much of the drug is avaible for use by the cells fter its been broken down Enzymes: protein that change one biochemical compound to another can increase or decrease bioavailability Small intestine: oral gastro drugs mostly absorbed in small intestine This required both lipid solubility and water solubility
Theophylline
Medication used to treat asthma. Opens up the airways.
The axons of a neuron may transmit electrical activity to ______. A) Muscles B) Organs C) Other neurons in the brain B) All of the above
All of the above
What effects the response of a drug dose between individuals? Metabolism Emotional state Previous drug use All of the above
All of the above
Blood Brain Barrier (BBB)
Not all drugs are psychoactive The BBB is the capillaries of the brain Most Capillaries: WEAK! Brain Capillaries: STRONG
Pharacodynamics
Drugs typically act on cells via receptors Receptors evolved to respond to natural substance in the body Drug causes some action in that cell
drug elimination
removal of a drug from the body
Acute(short term) effects of alcohol
- sedation - loss inhibition - impaired judgment - slurred speech and ataxia -increase dopamine -euphoria -short term eidheralp
Proof (alcohol)
Numerical value that is double the percentage of alcohol
How do we get drugs into the body?
Oral-digestion Membrane -oral -nasal -other membranes Pulmonary/respiratory Injection Transdermal(through the skin)
Water Solubility
Our tissues contain lots of water. Drugs that are water soluble diffuse into the blood stream quickly and easily
Artery
Oxygenated blood pumped from the heart through arteries Oxygenated blood passes through tissues in the capillaries Vein: De-oxygenated blood drains back to heart
parasympathetic/sympathetic nervous system
Parasympathetic: function is to conserve/restore your body's energy Sympathetic: flight or fight response
Alcohol flush reaction
People who flush when they drink are less able to break down acetaldehyde More common in women and east asians >4 drinks a week increases risk of high blood pressure, stroke and heart today
Do you think the speed at which you feel a psychoactive drug could affect how addictive it is?
Yes, it could make the drug more addictive or be a more impactful experience if it has a quick/instant on set.
How long does it take for drug to reach the brain when inhaled?
Almost instant
Which of the following is most closely associated with depression? Serotonin Dopamine GABA
Serotonin
Adenosine
a nucleoside; a combination of ribose and adenine; serves as a neuromodulator in the brain
Steps of Pharmacokinetics
absorption, distribution, metabolism, excretion
Major parts of the circulatory system
(from top down) -Vasculature of head/arms -Lungs (pulmonary)-Inhale to supply oxygen to body -Heart-pumps blood through the body -Veins-drain deoxygenated blood, towards the heart -Arteries-supply oxygenated blood, away from the heart -Liver-enzymes in the liver are the major way drugs are metabolized -Smal Intestine -Kidneys-important for drug elimination and metabolic byproducts -LUNGS-exhale to eliminate CO2 -Vasculature of legs/feet
Norepinephrine, acetylcholine, dopamine, serotonin, and amino acids are examples of _______.
Neurotransmitters
Anxiety and insomnia as a result of taking an anti-depressant are an example of what?
Side effects
Tolerance
you get used to the effects of a drug so you need more of it to get the same effect
Health risks of alcohol
§Sexual behavior §Alcohol use may enhance interest in sex but impair physiological arousal §Linked to risky sexual behavior (e.g. unprotected sex) §A factor in sexual assaults §Blackouts §Memory lapse, time period where person was conscious but can't remember a period of time. §A danger sign of excessive alcohol use §Crime and violence §Alcohol use is statistically related to: §Homicide §Assault, including family violence, sexual assault,suicide
Benzodiazepines
-most widely prescribed sedatives -prescribed as sleep aids and anti anxiety -enahnces response to GABA -opens up chloride channels making cells more resistant to excitation with positive ions. Neuron is less likely to fire. -legally prescribed but addictive -there is a potential for recreation use/abuse -don't demonize the drug, anxiety can be a serious and depilating condition -patients and docs should decide best treatment -clean=specific effect on GABA receptors -dirty=broad cascade of effects on GABA
barbituarates
-mostly absolute drug with more potential for overdose (higher therapeutic index) -largely been replaced by Benzodiazepines for sleep and anti anxiety -still used medically for anesthesia, epilepsy some intractable, migraines,
Gasotransmitters
Signaling molecules (gases) made in organisms body or originating outside the organism that are used to transmit chemical signals which induce physiological or biochemical changes in the organism, tissue or cell
Depressants (major effects and major subgroups)
-sedative=calming, reduction in anxiety -hypnotic-drowsiness, induction of sleep -tranquilizers, anti-anxiety, medication, sleeping pills, downers -depressants slow activity in central nervous system -slow reaction in CNS -slow reaction time and processing speed -think and act more slowly -interferes with REM sleep (memory) -removes inhibitions Includes -alcohol -barbiturates -benzodiazapines
Stimulants
-substances that can keep a person going mentally and physically -restricted stimulants: cocaine, and amphetamine -medically used
Oral Ingestion Digestion/gastrointestinal Digestive System
Absored into gastrointestinal tract Digestive System Mouth Throat Stomach Esophagus Small Intestine Large Intestine (elimination)
Describe the steps in an action potential
1. Neuron Fires: -the combines messages generate an electrical impulse 2. Axon -the impulse travels to the end of the axon 3. Neurotransmitters -the impulse causes neurotransmitters to be released from the axon 4. Synapse -neurotransmitters move across the gap (synaptic cleft) between neurons 5. Receptor -some neurotransmitters attach to special receptors on the receiving neuron 6. Message Received -messages are received on dendrites or on the cell body 7. Recycle -neurotransmitters are cleared from receptor sites and the synapse 8. New message -a new impulse can start in the receiving neuron
If a drug's elimination half life is 1 hour, how many hours until it is eliminated or changed completely in the body 7 minutes 7 hours 7 days 7 weeks
7 hours
Transdermal (through skin)
Skin absorption Thin skin vs thick skin (hairless) Skin patch -adhesive, rate controlling membrane, reservoir, backing
Acetylcholine
A neurotransmitter that enables learning and memory and also triggers muscle contraction
How does the speed of absorption impact the behavioral effects of a drugs?
A persons experience taking a drug that has immediate effect. For some people it might feel like too much too soon and freak them out, maybe more likely to get addicted if it's quick. More time to adjust with slower drugs,
Distillation
A process that separates the substances in a solution based on their boiling points
Pro/Con of transdermal administration
ALL OF THESE COULD BE PRO and CONS Slow release limited number of lipophilic drugs can pass through the barrier of the skin most of drug is not absorbed variability in human skin across people variability in human skin within people
Which of the following is/are true of alcohol elimination? A. Some alcohol is eliminated unchanged through the breath and skin B. Some alcohol is metabolized in the stomach C. 90% of alcohol is metabolized in the liver D. Some alcohol is excreted in urine E. All of the above
ALL of the above
How is alcohol consumed, absorbed and distributed throughout the body? aka pharmacokinetics of alcohol
Absorption -most absorbed in the villi/capillaries of the small intestine -some absorbed in the stomach -slower if there is food or water in the tummy Non-Gastrointestinal Absorption -can be absorbed through nasal cavities, enema or tampon or through thin mouth tissue -these methods bypass first-pass metabolism -more difficult to titrate dose -increased chance of brain toxicity -smoking alcohol(fast onset, recondenses in the lungs with potential adverse health consequences_ Distribution -blood alcohol concentration -easily passes through BBB -the measure of the concentration of alcohol in your blood expressed as a percentage in terms of grams per 100 ml -BAC increases when the absorption rate is greater than the elimination rate -everything from small intestine has to pass through liver to get to the brain
How do cells communicate?
Action potential: a brief electrical change in a synaptic neuron's charge that communicates with downstream postsynaptic neurons.
Active Transport
Active transport gets large molecules into the brain that the brain needs. Some drugs act like a Trojan horse and use these active transport mechanisms to sneak in.
Downers
Alcohol Barbituates Benzodiazepines
Mechanism of Action
Alcohol enhances the inhibitory effect of GABA Alcohol blocks the effects of the excitatory transmitter glutamate Effects on the dopamine system Increase dopamine in the mesolimbic system Reinforcing, rewarding effects Acute use Increase dopamine release (feel reward) Short term withdrawal effects, less reward than usual Chronic use Decrease dopamine release and down-regulate receptors Leads to less reward from normal pleasurable or rewarding things
Alcohol Behaviroal Effects
Alcohol is a solvent It dissolves organic compounds like lipids Mood changes can include -euphoria -reduced anxieties -reduced inhibitions Effects depend on the TIME COURSE -ex: greater effects are greater when ABC rises fast Effects are influenced by the individuals' alcohol experience -ex: higher BAC is needed to impair chronic heavy drinker Effects are influenced by expectations Ex: placebo effects explain many of the effects on social behavior
Membrane Absorption (oral, nasal, other membranes)
All highly vascularized (capillaries close to the surface) Drug can be dissolved and absorbed under the tongue (chewing tobacco, lsd, cbd, coca leaves Drugs can be snorted(skin is highly vascularized) aka cocaine, crushed pills Other: Rectal or vaginal, urethra, eyes (skin is highly vascularized)) suppository, liquid enema, ointment
Alcohol exerts its intoxicating effects through: A. GABA & Glutamate B. Dopamine C. Endorphins D. All of the above
All of the above
Psychoactive drugs are unique because they affect neurons in our ____ changing our thoughts, emotions, or perceptions. Peripheral Nervous System Central Nervous System Blood Liver
Central Nervous System
Alcohol by volume
Amount of alcohol in beer in terms of percentage volume of alcohol per volume of beer. CHANGE
How does transmitter removal occur
An enzyme present in the synaptic cleft breaks down any neurotransmitter lingering within the synapse OR the neurotransmitter is taken back into the presynaptic cell through the 12-helix reuptake transporter receptor present on the presynaptic membrane.
Which type of half life is impacted most by the rate of a drug's metabolism? A. Distribution Half Life B. Elimination Half Life
B. Elimination Half Life
Lipid Solubility
But our cells have fatty membranes called lipid bilayers. Oil and water don't mix. Fats are hydrophobic (afraid of water) For a drug to get into circulation through the intestinal wall it needs to be fat soluble
cocaine
Cocaine -leaf form -paste -white powder form -chewing or sucking leaves-slow absorption and onset of effects -insufflation (snorting) or cocaine -absorbed through nasal mucous -rapid absorption and onset of effects Intravenous injection -rapid and brief effects Smoked-freebase, crack cocaine -most rapid and most brief effects Coca Leaves -grown in the Andes -Inca culture -reduce fatigue and increase productivity -coca wine -coca leaf extract -slower onset and longer duration
Pros/Cons Oral Administiration
Con When drugs is needed immediately for lifesaving measures When the drug has low bioavailability Pros Easy to take When the drug is highly toxic
Hypothalamus
Functions: Body Temperature Basic Emotions Hunger Thirst Sleep/Wake Cycles Alcohol exerts effects on temperature thirst, sleep cycles
Cerrebellum
Functions: Movement Balance Posture Trouble with balance and walking due to alcohol's effect on cerrebellum
The main structural components of a typical neuron are
Dendrites, soma/cell-body, axon
Distribution Half Life
Distribution half life is the TIME it takes for drug to reach half of its max concentration Relates to the time it takes to distribute a drug though tissue (body water and fat) A Half Life is a way to describe a curve with a single number Imagine the body as a cup of water, various processes determine how long it takes the drug to be distributed through tissues after the initial dosage.
Additive Effects
Drug interactions in which the effect of a combination of two or more drugs with similar actions is equivalent to the sum of the individual effects of the same drugs given alone.
Dose Response Curve/Therapeutic Index
ED50= effective dose (dose required to produce a therapeutic effect in 50% of the population) TD50 -toxic dose -for 50% of the population A large therapeutic index means the drug is safer than one with a small therapeutic index
Hippocampus
Functions: learning and memory The hippocampus is one part of the limbic system that is important for memory and learning. Alcohol blackouts are due to its effects on the hippocampus
Drug Elinimation
Excreted unchanged through skin, breath, urine or bowel Pee, Poop, B.O, bad breath excretion via kidneys to urine drug can be unchanged drug metabolites can also be exerted long after effects of drug are over
True or False: Any substance that crosses the BBB is psychoactive.
FALSE-it must have a way to affect the brain
Intestinal Villi
Finger-like extensions of the intestinal mucosa that increase the surface area for absorption Drugs must be water and fat-soluble to get through cell walls and into the capillaries Drugs are absorbed into capillaries of small intensities
Methanol
For simple alcohol. Much more toxic than ethanol. alcohol in 'poorly made' moonshine. Very dangerous and can make you blind.
Long Term Effects (chronic) of alcohol
In n alcohol present-- decreased dopamine release and downregulate receptors leads to less reward from normal pleasurable or rewarding things Brain tissue loss and cognitive impairment Heart disease Alcohol-related pancreatitis cancer of the breast, mouth, throat and esophagus liver and colon liver disease The liver increases enzymes that metabolize alcohol à tolerance. • Brain also maintains homeostasis "Up-regulated"glutamate receptors (NMDA) "Down-regulated" GABA receptors The brain is adapting and attempting to get back to homeostasis No alcohol present àoveractivity àseizures, cell death
Pulmonary
Inhalation -smoking -inhaler for asthma -laughing gas Nasal/oral cavities larync and treachea lung bronchi alveoli capallaries pulmonary artery
Injection
Intravenous (direct to vein) Intradermal (think derm aka skin) -skin popping -heroin Intramuscular -into muscle -flu shot Subcutaneous -under skin -insulin Medical special case: spinal anethesia -epidural
What does it mean for a molecule of a drug to have higher potency than that of another drug?
It elicits a greater response from the cell
How do things pass the blood-brain barrier?
Large molecules do not pass BBB Molecules with low levels of lipid solubility do not penetrate the brain Lipid soluble molecules such a barbiturate drugs, rapidly cross through into the brain. Molecules that have a high electrical charge are slowed Active transport gets large molecules into the brain that the brain needs. Some drugs act like a Trojan horse and use these active transport mechanisms to sneak in.
Mechanisms of Action for Alcohol
Main neurotransmitter actions -enhances the inhibitory effect of GABA at the GABA receptor Blocks the effects of the excitatory transmitter glutamate Affects dopamine and opioid systems Alcohol causes changes practically every aspect of neuro conduction and neurotransmission Can change things like how soluble membrane is to different substances interact Affects membranes and receptors Most drugs alter functions only at the synapse, alcohol causes changes practically every aspect of neuroconduction & neurotransmission. Can change things like how soluble membrane is to different substances, interact with channel protein directly, change release of NTs Alcohol works on lots of different NTs (glutamate, GABA, dopamine, opioid receptors)
Brain Stem
Medulla Pons Midbrain Located between spinal cord and pons. Functions:cardiac, respiratory, vomiting, heart rate, breathing and blood pressure.Many key life or death functions High levels of alcohol can suppress these functions and be fatal
blood alcohol metabolism
Metabolism -liver metabolizes about 1/4 ounce of alcohol per hour Metabolism is based on a stable rate -"zero-order metabolism"-meaning a constant rate of elimination per unit time (a straight line) Liver adapts to chronic intake of alcohol by increasing enzyme activity -contributes to tolerance among heavy users For heavy alcohol users who have adapted to high alcohol intake -when alcohol is present, the metabolism of some other drugs is slower -when alcohol is not present, the metabolism of some other drugs is faster About 2% of alcohol is excreted/eliminated unchanged (breath, skin, urine) About 90% is metabolised in the liver Remainder is metabolized by enzymes in the rest of the body Alcohol---Alcohol dehydrogenase (enzyme #1)---Acetaldehyde---Aldehyde dehydrogenase (enzyme #2)---Acetic acid
Pharmaco Kinetics
Movement of drugs Determines a drugs actions Onset-when it starts Strength-how strongly it acts Duration-how long the effects last *Dose, the amount of drug taken, can affect other things like duration, strength and onset*
Neural Circuitry
Neuron Cell Body=grey matter Dendrite=gray matter Axon=white matter Myelin Sheath=white matter Synapse Neurotransmitter
How do networks of neurons become connected?
Neuroplasticity Neurons that fire together wire together Neurons out of sync, fail to link
How do enzymes regulate neurotransmitter availability?
They break down neurotransmitters
You enter into a clinical depression study and are directed to take a pill once a day for 6 weeks. You report daily that your mood seems to be improving and you feel less depressed. At the conclusion of the study, you learn that you were given a pharmacologically inert substance, despite feeling significant therapeutic responses. What were you taking? Serotonin reuptake inhibitor Monoamine oxidase inhibitor Benzodiazepine Placebo
Placebo
What are the 3 main parts of the brain stem?
Pons Medulla Midbrain
Possible causes of a hangover
Possible causes:§alcohol withdrawal, exposure to congeners (toxic byproducts of fermentation/distillation), dehydration, stomach upset, reduced blood sugar, and/or the accumulation of toxic byproducts of metabolism (e.g. acetaldehyde).
Pros/Cons of injection
Pro -precision -efficiency -quicker onset -bypasses first pass metabolism Con -infection from dirty needles (HIV/Aids) -pain and bruising -administration risk -long term use=damage to veins/clotting/collapsed veins
What does the BBB do?
Protects the brain from foreign substance in the blood that may injure the brain Protects the brain from hormones and neurotransmitters flowing through the rest of the body for other functions Maintains a constant environment for the brain
True or False? A drug cannot be psychoactive without getting past the blood brain barrier.
TRUE
True or False: Every drug that enters circulation will pass through the liver at some point.
TRUE But only gastrointestinal administration goes through First pass metabolism in the liver before entering circulation
Elimination Half Life
The amount of time for the drug concentration to decrease by 50% in the blood Represents primarily metabolic elimination Metabolic processes largely determine how long it takes the drug concentration to be reduced. Passive excretion only reduces the concretion a little bit Most drugs are changed or completely eliminated from the body in about seven of these elimination half lives
Drug Potency
The amount required to achieve an effect of a given intensity More potent drugs: a smaller amount for a larger effect.
Role of the heart
The heart pumps the blood supply through the entire body circulating this blood about once a minute
The hypothalamus is...?
The principle center in the brain responsible for the integration of our entire autonomic (involuntary or vegetative) nervous system. Hormones, body temp, etc.
Does the structure of synaptic buttons change how they affect the post synaptic neuron?
The shape and size of the axon terminal buttons and the dendrite spines affects the strength of their connection
Pharmacodynamics
The study of the interaction of a drug on receptors and how it effects behavior, physiology, or pharmacology
Agonist Drugs (not natural)
These drugs mimic natural agonist within the body, binding to receptors to create the same effect but often with a much more significant physiological response
If you reduce glutamate neurotransmitter release with some drug over a long period of time, the glutamate receptors will _______. A.Up-regulate B.Down-regulate
Up regulate
Withdrawal
When the drug is not available, you experience an effect opposite that of the drug
Drug Interactions
When two drugs are used together, their effects can be additive (the result is what you expect when you add together the effect of each drug taken independently), synergistic (combining the drugs leads to a larger effect than expected), or antagonistic (combining the drugs leads to a smaller effect than expected)
basal ganglia
a set of subcortical structures that directs intentional movements
Amphetamine
a type of stimulant often used to stay awake or to reduce appetite stimulated central nervous system
A drug that mimics the action of a neurotransmitter is termed a(n) ______________ for that transmitter, where a drug that blocks access of a neurotransmitter to its binding site, inhibiting action of the transmitter is termed a(n) ________________ for that transmitter.
agonist, antagonist
Why is alcohol addictive?
alcohol is a 'dirty drug' that affects GABA, Glutamate, Opioid, and Dopamine systems. Reinforcing, rewarding effects
barbiturate
any of a class of sedative and sleep-inducing drugs derived from barbituric acid.
Astrocyte
are characteristic star-shaped glial cells in the brain and spinal cord. The proportion of astrocytes in the brain is not well defined.
Drug in circulation access cells through the...?
capaliaries
Major Categories of Drugs
depressants stimulants opioids/narcotic analgesics hallucinogens inhalants cannabis other psychoactive agents Antipsychotics Antidepressants
first pass metabolism
drug metabolism that occurs in the intestines and liver during oral absorption of drugs into the systemic circulation must pass through liver before going to the brain
Drug Absorption
entrance of a drug into the bloodstream from its site of administration
Drug Abuse
intentionally using drugs in a way that is unhealthy or illegal
Define the following and be able to identify on an image of cell: Neuron Dendrite Axon Hillock Axon Terminal Buttons Synapse Pre-Synaptic Post-Synaptic Ion Channels Receptors
khkgk
A _______ therapeutic index means a drug is safer than one with a ________therapeutic index.
large, small
Metabolites
molecules made or broken down in the body
Limbic System
neural system located below the cerebral hemispheres; associated with emotions and drives
Drug Distribution
passage of a drug from the blood to the tissues and organs of the body
Alcohol passes through the BBB via??
passive diffusion through the capillary walls because it is small and is both lipid soluble and water soluble.
Sympathomimetic
pertaining to mimicking or copying the effect of the sympathetic nervous system
fetal alcohol syndrome
physical and cognitive abnormalities in children caused by a pregnant woman's heavy drinking alcohol easily crosses the placental barrier affecting the developing fetus-body and brain related to peak BAC, to duration of alcohol exposure and gestational timing 1.Growth retardation before and/or after birth 2.Pattern of abnormal features of the face and head 3.Evidence of CNS abnormality -structural and functional brain dysfunction
Drug addicition
physical or psychological dependence on a drug or medication. You need the drug to feel or function normally
Enzymes
protein that change one biochemical compound to another can increase or decrease bioavailability
Natural agonists
substances within the body that have evolved to produce a response when they bind to and switch on receptor
In what ways do neurons change with repeated stimuli?
size of dendrite contact point number of receptors on dendrite Number of vesicles in axon terminal size of electrical signal
What is one drink?
standard drink has about 1/2 ounce of pure ethanol {aka "alcohol} -12 oz of 4% ABV of beer -4 ounces of 12% ABV wine -1 ounce of 100 proof spirits (50% alcohol by volume)
Xanthines
the class of chemicals to which caffeine belongs
drug metabolism
the conversion of a drug from its active form to a nonactive form
drug misuse
the incorrect use of a prescription or OTC drug
Meninges
three protective membranes that surround the brain and spinal cord
Alveoli
tiny sacs of lung tissue specialized for the movement of gases between air and blood surface area of tennis court tight web of capillaries around each "grape" Lungs go straight to heart which circulates blood through the body and brain
down regulation/up regulation
up regulation: target cells form more receptors in response to the hormone down regulation: target cells lose receptors in response to the hormone
Hydrophilic
water loving
Addiction
when you crave the drug and seek out the drug even though it interferes with normal functioning relationships, and your health
(physical)dependence
when you need the drug to feel normal