Psychoactive Drugs - PowerPoint PPT Presentation

1 / 61
About This Presentation
Title:

Psychoactive Drugs

Description:

Most drugs are broken down into metabolites (by-products ... 70s-80s cocaine becomes 'chic' with jetset. & cheap 'crack' cocaine becomes hit in poor areas. ... – PowerPoint PPT presentation

Number of Views:156
Avg rating:3.0/5.0
Slides: 62
Provided by: PanamaCi7
Category:

less

Transcript and Presenter's Notes

Title: Psychoactive Drugs


1
Psychoactive Drugs
  • Dr. Kline

2
I.  How drugs are handled by the body?
  • 1.     Absorption into the body.
  •  2.     Distribution of the drug through the
    body, including the fetus, at time drug is taken.
  •  
  • 3.     Metabolism the detoxification of the
    drug by the body (liver). Most drugs are broken
    down into metabolites (by-products or waste) that
    no longer exert an effect.
  •  
  • 4.     Elimination of the drug, usually
    excreted through urine.
  •  

3
Six routes of drug entry into body
  • 1.     Orally (tablets, capsules, liquid)
  • 2.     Rectally (suppositories)
  • 3.     Intravenous (injected in liquid form
    through a needle into the skin)
  • 4.     Inhaled through the lungs (as gases,
    vapors, or particles)
  • 5.     Through skin (patches on skin)
  • 6.     Through mucous membranes (snorting or
    sniffing under tongue)
  •  

4
How drugs act on the system
  • The pharmacological, physiological, or behavioral
    effects induced by a drug follow their
    interaction with receptors.
  • This is called pharmacodynamics involves the
    mechanisms of drug action that occur at the
    molecular level.

5
Drugs produce effects by
  • binding to interacting with specialized
    receptors, located on the synapses of neurons.

6
What are receptors?
  • A receptor is a large molecule on the cells
    surface where endogenous compounds
    (neurotransmitters) induce their normal effects.
  • Usually only 1-2 neurotransmitters is specific
    enough to fit or bind to a specific receptor.

7
Binding to receptors
  • 1.    A drug that binds to a receptor normally
    occupied by a given transmitter can initiate a
    cellular response similar or identical to that
    exerted by the transmitter.
  • The drug mimics the action of the transmitter.
    Here, the drug is an agonist for that
    transmitter.  
  • 2.  A drug that binds to a receptor blocks the
    neurotransmitter from stimulating the cell is
    called an antagonist.

8
II. Dose-Response Relationships
  • A dose-response curve may be plotted as
  • the dose of a drug given as a function of the
    of people who show an effect at a given dosage.

9
Drug Effectiveness
  • The dose of a drug that produces the desired
    effect in 50 of subjects tested is called the
    ED50.
  • The lethal dose for 50 of subjects (animals) is
    called the LD50.
  • The ratio of the LD50 to the ED50 is used as an
    index of the relative safety of the drug is
    called the therapeutic index.

10
III. Drugs
  • A. ALCOHOL (ethanol)
  • Alcohol is found in different concentrations
    in liquid
  • -12 in wine
  • -3.5-5 in beer
  • -40-50 in liquors
  • It is most often expressed as proof which is
    twice the percent concentration (i.e., 80 proof
    40 ethanol).

11
Alcohol absorption
  • Alcohol readily diffuses across all biological
    membranes is completely absorbed by the entire
    GI tract.
  • Alcohol usually takes 30-90 minutes to reach
    peak levels in the blood.
  • About 20 of a single dose of alcohol is
    absorbed directly via the stomach.
  • The remaining 80 is absorbed rapidly by the
    large intestine.

12
Alcohol metabolism
  • 85 by liver
  • 2-5-by lungs (can be detected by breath)
  • 10-15- broken down by stomach enzymes.
  • A full stomach reduces a persons blood alcohol
    level, because the enzymes have longer time to
    metabolize the alcohol.

13
Who has the higher blood alcohol level, men or
women?
  • Women!!!
  • 1.  Women --50 less gastric metabolism of
    alcohol, because they have lower levels of
    gastric enzymes.
  • 2.  Since men have greater ratio of muscle to fat
    than do women, alcohol is more diluted in their
    blood (fat has little blood supply in contrast to
    muscle).
  •  

14
What are the effects of alcohol?
  • 1. Physiological effects-
  • Slows Respiration (CNS depressant)
  • Sedative effects are additive when combined with
    other depressants (e.g., barbituates).
  • Dilates blood vessels in skin (decreases body
    temp blushing).
  • Lowers cholesterol (low doses) by lowering LDL
    increasing HDL.
  • May cause heart damage (high doses-5 drinks per
    day).
  • May cause liver damage (high doses over time)

15
2. Psychological effects
  • Behavioral disinhibition (low doses)
  • Euphoria (low to moderate doses)
  • Violent or irascible mood (moderate to high
    doses)
  • Memory, concentration, insight are impaired
  • Reaction time is impaired
  • Motor system is impaired (cerebellum)
  •  

16
How does alcohol produce its effects?
  • 1. Alcohol is a GABA agonist, it facilitates
    expression of GABA (inhibitory transmitter).
    Contributes to behavioral disinhibition, motor
    slowing.
  • 2. Alcohol inhibits glutamate (excitatory
    system). Receptors, which may cause cognitive
    effects of alcohol intoxication, such as slurred
    speech memory loss.
  • 3. Alcohol increases levels of dopamine
    serotonin, likely providing both euphoric
    sedative effects.

17
B. MARIJUANA
  • Dried crushed leaves flowering tops of the
    hemp plant, Cannabis sativa.
  • Major ingredient-- delta-9-tetrahydrocannabinol
    (THC)
  • Marijuana has 2-5 THC
  • May be smoked, chewed, or eaten (in baked goods).

18
What are effects of marijuana?
  • 1. Physiological effects
  • Produces analgesia
  • Has antiemetic properties (decreases nausea
    vomiting)
  • Increased HR blood pressure
  • Dilated blood vessels in eyes (bloodshot eyes)
  • Sedative effects

19
2. Psychological effects
  • Shifts in emotion
  • Disrupted attention
  • Impaired STM
  • Altered sensory perception
  • Time distortions (time moves more slowly)
  • Motor activity impaired
  • Hallucinations (with heavy doses)
  • Panic (with heavy doses)

20
How does marijuana produce its effects?
  • We have cannabis receptors in the brain. These
    receptors are found in the
  • 1. basal ganglia (fine motor system)
  • 2. cerebellum
  • 3. cortex (especially the frontal lobe)
  • 4. hippocampus
  • We dont have any cannabis receptors in the
    brainstem. THC does not affect basal body
    functions.

21
Do we have a transmitter substance like THC in
our brains?
  • Yes!!! We have anandamide which binds to
    cannabinoid receptors produces cannabinoid-like
    pharmacological effects.

22
C. HALLUCINOGENS
  • 1. LSD
  • First synthesized in 1938, as a compound of ergot
    (a fungus that grows on rye) by Hoffman.
  • Hoffman accidentally ingested the drug noticed
    its unusual effects.
  • During 1950s, LSD was used as a model for
    examining treating psychosis was also used in
    therapy.

23
LSD administration
  • Is taken orally.
  • ED50 is 25 micrograms to 300 micrograms.
  • Usually is found on sugar cubes, stamps, candy
    dots
  • Is absorbed within 1 hour peaks in 3 hours.
  • Duration 6-8 hours.

24
What are the effects of LSD?
  • 1. Physiological Effects
  • Slight increase in body temperature
  • pupil dilation
  • slightly increased HR blood pressure
  • dizziness nausea

25
2. Psychological Effects
  • 1.     Altered perception, thinking, emotion,
    arousal
  • 2.     time distortions (slowed)
  • 3.     Intense visual auditory hallucinations
    (trasers)
  • 4.     Cross-sensing (hearing colors seeing
    sounds)
  • 5.     emotions shift rapidly (happiness to pit
    of despair)
  • 6.     tension anxiety make lead to panic
  • 7.     psychotic experience

26
How does LSD produce its effects?
  • LSD exerts its effects by interacting with
    serotonin receptors (5-HT receptors).
  • Most researchers argue its a serotonin agonist.

27
2. MESCALINE
  • Comes from the crown or button of the peyote
    cactus.
  • The crown is dried into a hard brown disk that
    softens when ingested.
  • Is absorbed in 1-2 hours.
  • Effects occur between 3.5 4 hours after
    ingestion. Vivid hallucinations most salient.
  • --trip is long (10 hours)
  • Right frontal activity seems to be high in people
    on mescaline. Agonistic for norepinephine
    serotonin.

28
3. PSILOCYBIN
  • Found in mushrooms (genera Psilocybe).
  • Mushrooms are eaten raw.
  • mushrooms grow through out world, including
    northwestern US.
  • It peaks in about 2 hours, effects
  • last 6-10 hours.

29
How does it produce its effects?
  • It appears to exert its effects as a serotonin
    agonist that stimulates 5-HT receptors especially
    in the frontal areas.

30
4. MYRISTIN ELEMICIN
  • Are agents found in nutmeg mace, two common
    household spices.
  • ED50--1-2 teaspoonsusually brewed in tea
  • Within 2-5 hours, you get symptoms similar to LSD
    (euphoria, visual hallucinations, psychosis,
    etc.)
  • However, most people experience vomiting, nausea,
    tremors prior to the trip making it a one
    time event for many.

31
D. STIMULANTS
  • In general these drugs
  • increase behavioral activity
  • elevate mood
  • increase alertness
  • allay sleep
  • increase brains metabolic neuronal activity.

32
1. COCAINE
  • Comes from the coca plant (Erythroxylon coca)
    found in South America.
  • The active alkaloid in E. coca was isolated in
    1855, purified in 1860, named cocaine.
  • In late 1800s, cocaine was used as an anesthetic
    (spinal, local), was added to medicines
    Coca-Cola.
  • It was banned from use in medicines beverages
    in 1914 in the Harrison Narcotic Act.

33
COCAINE (history)
  • By 1930s, amphetamines replaced the popularity of
    cocaine.
  • 1960s- cocaine makes a comeback when amphetamines
    become pricey.
  • 70s-80s cocaine becomes chic with jetset.
  • cheap crack cocaine becomes hit in poor
    areas.
  •  

34
Forms of cocaine
  • Cocaine can be snorted, smoked, taken orally, or
    injected intravenously.
  • Powdered cocaine (cocaine hydrochloride) 25 mg
    per line.
  • Crack cocaine- (250 mg-1 gm) per smoke.

35
Physical Effects
  • Vasoconstrictor
  • Increases norepinephrine dopamine
  • Tachycardia
  • Stroke, seizure, heart attack
  • Increased blood pressure
  • Local anesthetic

36
Psychological Effects
  • Euphoria
  • Elevated mood
  • Agitation
  • Flight-of-ideas
  • Grandiose thoughts

37
How does it produce its effects?
  • Cocaine blocks reuptake of dopamine,
    norepinephrine, serotonin, thereby increasing
    them in the CNS.
  • Increasing dopamine levels in dopaminergic reward
    system results in euphoric/addictive effects of
    drug.

38
2. AMPHETAMINES- Effects
  • Vasoconstriction
  • Hypertension
  • Tachycardia
  • Increased motor activity
  • Loss of appetite
  • Restlessness/tremors 
  • hallucinations (amphetamine psychosis)
  • Paranoid delusions

39
Amphetamines-today
  • 1.  Therapeutic use in the treatment of
    narcolepsy ADHD.
  • 2.  To treat compulsive misuse of methamphetamine
    (amphetamine derivative).

40
How do amphetamines cause their effects?
  • They cause release of norepinephrine dopamine
    from presynaptic storage sites in nerve
    terminals.
  • Peripheral NS activity --increased norepinephrine
     

41
ICE- form of methamphetamine
  • Was originally used to treat ADHD, now mostly an
    illegal street drug.
  • Street names of drug Speed, crystal, crank, go,
    ICE.
  • Methamphetamine--orally, by IV injection,
    snorted. The base form (ICE) can be smoked.
  • ICE-methamphetamine, crack-cocaine. Its the
    free-base, smokable form of the parent compound.

42
3. CAFFEINE
  • The most common psychoactive drug in world.
  • Consumed -80 of adult population.
  • 1 cup of coffee---50-150 mg of caffeine.
  • Caffeine content of chocolate--25 milligrams per
    ounce.
  • Average intake 3-5 cups of coffee every day.

43
Absorption
  • Significant blood levels of caffeine are reached
    in 30 to 45 min with complete absorption in 90
    min.
  • Peaks in about 2 hrs decreases thereafter.
  • The half-life is about 3.5 to 5 hours in most
    adults.

44
Effects
  •  
  • tachycardia
  • Increased Blood pressure
  • Vasoconstriction
  • Diurectic
  • Increased mental activity alertness
  • Increased wakefulness
  • Agitation
  • Tremors
  • Anxiety
  • Insomnia

45
 
  • HOW DOES CAFFEINE EXERT ITS EFFECTS?
  • Caffeine exerts its effects by blocking adenosine
    receptors.
  • Adenosine is a neuromodulator that influences the
    release of several neurotransmitters in the CNS.
  • It appears to exert sedative, depressant,
    anticonsulsant actions. Thus, blocking adenosine
    causes anxiogenic effects.

46
E. OPIATES
  • A group of addictive sedatives that in
  • moderate doses relieve pain induce sleep.
  • The original principle opiate was opium, which is
    extracted from poppy seeds of the poppy plant
    (papaver somniferum).
  • The psychoactive ingredient in opium is morphine,
    named for Morpheusthe Greek God of dreams.
  • Two drugs are found in the exudate of the poppy
    morphine codeine.

47
OPIATES-History
  • Opium--has been used for thousands of years to
    produce euphoria, analgesia, sleep, relief from
    diarrhea cough.
  • Ancient Greece Rome-- through the 16th-
    17th-centuries, opiums medicinal recreational
    uses were well established.
  • A mixture of opium and alcohol, called laudanum,
    was used to treat practically every disease known
    during the 1800s.

48
OPIATES-History
  • During the civil war, opium addiction was a
    widespread problem.
  • By 1914, the Harrison Narcotic Act was passed and
    the use of most opioid products was controlled.

49
Opiates vs. Opioids
  • Opiate-- is a drug that is extracted from the
    exudates of the poppy.
  • E.g., morphine and codeine.
  • An opioid is any exogenous drug (natural or
    synthetic) that binds to an opiate receptor
    produces agonist or morphine-like effects.
  • E.g., heroin, hydrocodone

50
Endorpins (morphine-within)
  •  Endorphins --any endogenous substance (naturally
    occurring in the body) that exhibits
    pharmacological properties of morphine.
  • We have 3 families of endorphinsenkephalins,
    dynorphins, beta-endorphins.

51
MORPHINE
  • Is still the most potent pain reliever available
    (no other drug has its clinical effectiveness).
  • Is administered orally, rectally, or by
    injection. Absorption is slow only 20 of the
    drug reaches the CNS.
  • Is broken down by liver produces metabolites
    (morphine t-glucoronide) that are 10 to 20-fold
    more potent that morphine itself. These continue
    exerting analgesic effects.
  • Morphines half-life 3 to 5 hours.

52
MORPHINE-DRUG TESTING
  • For 2 to 4 days following opiate use, urine
    screening tests can be used to detect codeine
    morphine as well as their metabolites.
  • Heroin use can be tested for indirectly. Heroin
    is metabolized to morphine also often contains
    acetylcodeine (metabolized form of codeine).
  • Although the tests cannot accurately determine
    which drug (heroin, codeine, morphine) was
    present.

53
WHAT ARE EFFECTS OF MORPHINE?
  • Analgesia
  • Relaxation
  • Euphoria
  • Sedation
  • Sense of tranquility
  • Reduced anxiety
  • Respiratory depression
  • Cough suppression

54
HOW DOES MORPHINE EXERT ITS EFFECTS?
  • Morphine, like other opiates opioids, exert its
    effects by stimulating opiate receptors widely
    distributed through the CNS (brain, brain stem,
    spinal cord).

55
 CODEINE
  • Is usually combined with aspirin or acetaminophen
    for the relief of mild-to-moderate pain.
  • Half-life--3 to 4 hours.
  • Codeine is metabolized by hepatic cytochrome
    CYP2D6 enzymes to morphine, many of its effects
    may be the result of morphine actions.
  • Using serotonin-specific antidepressants can
    block the pain relief of codeine, because they
    block the conversion of codeine to morphine.

56
HEROIN (diacetylmorphine)
  • Is produced by a slight modification of the
    chemical structure.
  • It crosses the blood-brain barrier very rapidly,
    leading to an intense rush when it is either
    smoked or injected intravenously.
  • It is metabolized to monoacetylmorphine
    morphine.
  • Clinical use of heroin is legal in Great Britain
    Canada.

57
F. ANTIDEPRESSANTS
  • A broad class of drugs used to treat depression.
  • What is depression???
  • A state of great sadness characterized by
    feelings of despair, worthlessness, hopelessness,
    withdrawal from other.
  • Its the common cold of psychopathologyweve
    all had symptoms at some point.

58
Major depression DSM diagnosis made if
  • Person has 5 of the following symptoms (next
    slide) for at least 2 weeks.
  • Depressed mood or loss of interest pleasure in
    enjoyable activities (anhedonia) must be included
    in symptoms.

59
Symptoms of major depression
  • 1. Depressed mood.
  • 2. Loss of interest and pleasure.
  • 3. Significant weight loss or weight gain.
  • 4. Difficulty in sleeping-Insomnia or
  • hypersomnia.
  • 5. Shift in activity level, psychomotor
    retardation, or agitated.
  • 6. Fatigue or loss of energy.
  • 7. Negative self-concept.
  • 8. Difficulty concentrating.
  • 9. Recurrent thoughts of death or suicide.

60
1. Tricyclics
  • E.g., imipramine (Tofranil) and amitriptyline
    (Elavil).
  • These prevent reuptake of both norepinephrine
    serotonin by the presynaptic neuron.
  • 2. Monoamine oxidase (MAO) inhibitors -
    tranylcypromine (Parnate)
  • Keeps enzyme monoamine oxidase from
    deactivating neurotransmitters, thereby
    increasing the levels of both serotonin and
    norepinephrine.

61
3. Selective serotonin reuptake inhibitors
(SSRIs) fluoxetine (Prozac) sertraline
(Zoloft). 
  • Selectively blocks reuptake of serotonin.
  • Efficacy of all three classes of drugs about the
    same (50-70 effective).
  • Side effects fewer in SSRIs. Tricyclics can be
    dangerous.
Write a Comment
User Comments (0)
About PowerShow.com