Transcript file (Poison Prevention Outreach Mt. Lebanon High School)

THE NEUROSCIENCE OF
DRUG ABUSE
Presented by Jon Ptachcinski, Samantha Allen, and
Melissa Ruminski
Basics of Drug Action
•
•
Many drugs work by
either activating a neuron
within a pathway
(excitatory or agonists)
or blocking spaces that
would ordinarily be
available for
neurotransmitters
(inhibitory or
antagonists)
Molecular shape mimics
chemicals present in your
nervous system
–
Ex. LSD mimics serotonin
Tolerance and Addiction

What is tolerance to a drug?
 Tolerance
is an increase in the dose of a drug (legal or
illegal) in order to achieve the same effect
 Metabolic or homeostatic
 Can lead to tolerance-based addiction
Tolerance and Addiction

Psychological Addiction

User gets “hooked” on the
effects of the drug



Ex. “Being drunk makes me
stop worrying about my
schoolwork”
Ex. “I’m much more effective
solving complex problems
when I’ve taken acid”
Can lead to anxiety,
depression, mood swings,
failed attempts to quit

Physical Addiction

User becomes physically
dependent on the presence
of the drug itself


Drug is needed to maintain
functioning of their nervous
system
Removal of the drug leads
to withdrawal (effects
opposite of the drug)



Shakes/tremors
Irritability
Insomnia
ABUSE OF OTC
MEDICATIONS
Trends in Teen OTC Abuse




10% of teens have abused cough/cold medications
1 in 4 teens know someone that abuses cough/cold
medications
Most common age 13-16yo
Treatment admissions linked to OTC abuse
increased >30% from 1993-2003
Most Commonly Abused OTC’s





Cough/cold medications
 Dextromethorphan (DXM): Robitussin
 Pseudoephedrine (Sudafed)  methamphetamine
Pain relievers
 Aspirin
 NSAIDs (Ibuprofen): Motrin
 Acetaminophen: Tylenol
Motion Sickness pills
 Dramamine
Diet pills/laxatives
Sexual performance pills
Why Abuse OTC’s?




Believed to be safer
Easily accessible
Cheap
Believe additional doses will produce additive
effects
Dextromethorphan


Synthetic cough suppressant compound
chemically similar to morphine
At high doses, converted to
dextrophan (similar to ketamine and
PCP)

Max dose 120mg/day

Abusers consume 360mg or more

100-200mg = mild stimulation

200-400mg = intoxication phase

300-600mg = “out of body”
experience

600-1500mg = full dissociate
phase
Dextromethorphan Side Effects






Hallucinations
Loss of motor control
Impaired judgement
Blurred vision
Brain damage
Cardiac dysrhythmia
Pseudoephedrine



Used as a
decongestant
Purchased in large
quantities for
conversion to
methamphetamine
Law prohibits the
purchase of more than
9g per month
Amphetamine side effects



Acute
 Euphoria, increased energy/attentiveness, sweating, loss of
appetite, insomnia, agitation, compulsiveness, irritability,
DNV
Chronic
 Craving/addiction, weight loss, tooth decay, withdrawalrelated depression
Overdose
 Brain damage, sensation of bugs crawling on skin,
rhabdomyolysis, stroke, heart failure, cardiac arrest,
hyperthermia
NSAIDs (ibuprofen or Motrin)



Ibuprofen max dose =
1200mg or 6 tablets
Similar
signs/symptoms
compared to aspirin
Less life threatening,
typically requiring a
massive overdose to
be fatal
Acetaminophen (Tylenol)



Commonly found in many
prescription pain
medications (vicodin,
percocet, darvocet)
Max dose =
4000mg/day
Acetaminophen is the
most common cause of
acute liver failure and
the leading reason for
liver transplants
Signs/symptoms of Acetaminophen Overdose


May not be present for 24 hours
Nausea, vomiting, and sweating at first, followed by a symptom-free
period





Acute liver failure may take up to 5 days to fully develop
Symptoms include hepatic encephalopathy, coma, hypoglycemia,
coagulopathy, cerebral edema, acidemia
Antidote available but must be administered early
Many patients require transplant
Mechanism of toxicity:



Metabolized in the liver to a reactive intermediate molecule (NAPQI)
Normally neutralized by a sulfyhydryl compound in liver (glutathione)
Glutathione depletion during overdose, so reactive NAPQI is available
to react with sulfyhydrl compounds in cytsol, cell wall, and endoplasmic
reticulum liver cell (hepatocyte) destruction
Dramamine



Max dose 400mg/day
Acts as a hallucinogenic and
deliriant at doses of 7501200mg
 Auditory/visual
hallucinations
 Confusion/short term
memory loss
 Coupled lead to paranoia
Extreme overdoses lead to
tachycardia, heart
palpitations, and potentially
fatal dysrhythmias
Diet pills/laxatives



Used to facilitate weight loss
Diet pill abuse can cause
insomnia, high blood
pressure, anxiety, and heart
complications
Laxative abuse is more
common and can cause
dehydration, electrolyte
imbalance, metabolic
acidosis, and physical
damage to the GI tract.
Laxative abuse is more likely
to be fatal
Sexual Performance Pills



Often used to counteract
the effects of alcohol on
sexual performance
Usually have function
related to amphetamines
and act as stimulants
Can cause potentially fatal
cardiac problems in
combination with alcohol
Key points




Don’t recreationally abuse OTC drugs!
Follow the directions on all OTC medications!
Know what’s in your medications, many are
combination products
1-800-222-1222
ABUSE OF PRESCRIPTION
MEDICATIONS
Trends in Prescription Drug Abuse



prescription drugs are the most commonly abused
drugs by teens
nearly all deaths due to poison in US from 19992004 result from abuse of prescription and illegal
drugs
nearly 1/5 teens (19% or 4.5 million) report
abusing prescription meds
Why Abuse Prescription Medications






relief of pain/anxiety
belief that these drugs are medically safe
sleep improvement
experimentation
help with concentration or alertness
easy to obtain
Most Commonly Abused Prescription
Drugs
Opioids
 CNS Depressants
 Stimulants

Opioids

examples:
 Vicodin
(hydrocodone/acetaminophen)
 Tylenol #3 (acetaminophen with codeine)
 Oxycontin (oxycodone)
 Dilaudid (hydromorphone)
 Kadian (morphine)
Opioids


Mechanism of action:
 Mimic the action of endogenous peptides (opiopeptins
like enkephalin)
 Bind at opioid receptors (m, k, d, s, e) in brain loci
Effects
 pain transmission at afferent and spinal cord neurons
 pain modulation in midbrain and medullary neurons
 pain reactivity at basal ganglia, hypothalmic, limbic
structures, and cerebral cortex neurons
Opiods
Opioids

Therapeutic use
 Narcotic
analgesia
 Cough suppressant

Illicit use
 Euphoria
 Dysphoria
 Apathy/confusion
 Sedation
 Attention
impairment
Adverse effects of opioid abuse
Effects of intoxication









Respiratory depression
Nausea/vomiting
Flushing of skin
Altered release of hormones
Slurred speech
Motor retardation
Decreased blood pressure
when standing
Constipation/urinary retention
Miosis
Withdrawal symptoms













Restlessness
Trembling
Rapid heart rate
Sweating
Hyperthermia/fever
Difficulty breathing
Pupil dilation
Chills (“goosebumps”)
Yawning
Runny nose/sneezing
Anorexia
Muscle pain/cramps
Kicking movements
CNS Depressants

Examples:
 Barbituates
 Phenobarbital
 Amytal
 Benzodiazepines
 Xanax
(alprazolam)
 Valium (diazepam)
 Ativan (lorazepam)
 Klonipin (clonazepam)
CNS Depressants

Mechanism of action:
 Enhance
the activity of inhibitory neurotransmitter
GABA
 Slow impulses throughout the body and inhibit motor
neurons

Effects:
 Anti-anxiety
 Sedation
CNS Depressants

Therapeutic use:
 Anxiety
 Sedation
 Muscle
spasms
 Sleep problems

Illicit use:
 Reduce
anxiety
 Lower amount of
alcohol required to
become intoxicated
Adverse effects of CNS Depressants
Effects of intoxication









Memory impairment
Drowsiness
Visual disturbances
Confusion
Intoxicated appearance
Low blood pressure
Urinary retention
Involuntary eye movements
Difficulty breathing
Effects of withdrawal


Seizures
Hallucinations
Stimulants

Examples:
 Adderall
(amphetamine)
 Ritalin (methylphenidate)
 Vyvanse (dislexamfetamine
Stimulants

Mechanism of action:
 Increase
activity of neurotransmitters (norepinephrine
and dopamine) by blocking reuptake, increasing
release or inhibiting degrdation

Effects:
 Decrease
fatigue
 Increase alertness
 Suppress appetite
Stimulants

Therapeutic use:

Illicit use:
 ADHD
 Euphoria/mood
 Narcolepsy
enhancement
 Increased wakefulness
 Increased physical
activity
 Decreased appetite
 Depression
Adverse Effects of Stimulant Use
Effects of intoxication




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Increased breathing rate
Irritability
Insomnia
Confusion
Tremors
Anxiety
Paranoia
Chest pain
Aggressiveness
Hyperthermia
Convulsions
Effects of withdrawal





Depression
Altered mental status
Drug craving
Fatigue
Sleep disorders
related to
sleeplessness
What is Cocaine?
Cocaine



a stimulant that can be
snorted (powder) or
smoked (crack)
made by drying the
leaves of a small tree
indigenous to the Andes
Mountains in South
America
to be used, the active
compound must 1st be
isolated from the leaves
in a multi-step chemical
reaction
Cocaine
Powder
Crack
Cocaine
Uses of Cocaine
There are 2 main uses for cocaine:

Therapeutic:


a local anesthetic prior to procedures of
the mouth, throat and nose
MOA: blocking the conduction of action
potentials down the nerves of the
peripheral nervous system
 Without these nerve impulses, the
body cannot deliver the message that
it is experiencing pain

Illicit:


a central nervous system (CNS)
stimulant resulting in an initial
feeling of well-being and euphoria
 This occurs by blocking the
reuptake of several
neurotransmitters including
serotonin, norepinephrine and
dopamine
Later on, it will lead to restlessness
and motor activity and several
other health problems due to
overstimulation of nerves
Effects on Health

CNS Effects
 At
first, stimulates the vomiting center in the brain
 This is followed by:
 Respiratory
depression leading to respiratory failure
 Depression of activity in the medulla
 Large doses can lead to death
 Also
causes an increase in body temperature by
effecting the heat-regulating centers of the brain
 “Cocaine
fever”
Effects on Health, cont.

Cardiovascular Effects
 Cocaine
causes constriction of the blood vessels,
increased heart rate and an acute increase in blood
pressure
 This
leads to an increased risk for stroke, seizures and heart
attacks
 In
the latter stages of the dose, blood pressure falls
and death could occur
 A large IV dose may cause immediate death due to its
toxic effects on heart muscle
Cocaine Abuse

Euphoria is more rapid and intense with smoking
“crack” due to its direct path to the brain and users
will smoke every 30 minutes to try to maintain this
euphoria
 Monkeys
consistently treated with cocaine will ALWAYS
choose cocaine over food, for up to 8 days

Cocaine produces the highest degree of psychic
dependence among all recreational drugs
 Abruptly
stopping after chronic use leads to profound
withdrawal symptoms
Cocaine Toxic Syndrome


Overuse can lead to hallucinations (visual, auditory
and tactile) including cocaine “bugs”
When using, nasal blood vessels constrict making
breathing easier
 but
after effects are finished, the vessels dilate causing
a stuffy nose and bleeding

Use can lead to states of panic and paranoia
What is Marijuana?

Marijuana comes
from the dried
flowering tops of the
Cannabis sativa plant


The plant is cultivated
for its fibers (hemp)
and fruit (hempseed)
The flowering tops
contain molecules
called “cannabinoids”
which produce the
pharmacologic effect
associated with
smoking marijuana
CH3
9
8
7
10
OH
10a
1
2
6a
H3C
H3C
6
3
O
5
4
9
CH3
 -trans-TETRAHYDROCANNABINOL
9
-THC (DRONABINOL)
THC is the cannabinoid
with major euphoric
properties
Clinical Uses

Antiemetic

Used to treat nausea
and vomiting associated
with chemotherapy in
those who don’t
experience relief with
medication

Appetite stimulant
 Used
in AIDS patients
who are experiencing
anorexia/weight loss
Illicit Use


People use marijuana because it can elevate mood
(euphoria) and cause relaxation and sleepiness
It can also lead to spontaneous laughter
Side Effects of Marijuana Use

CNS Effects


Short-term memory
impairment and inability to
perform tasks the require
several mental steps
Altered time perception


Psychotoxic at high dosages


Confusion between past,
present and future
Hallucinations, paranoia,
increased time distortions
Chronic users can suffer
from amotivational
syndrome
Side Effects, cont.

Cardiovascular Effects
 Increases
heart rate
 Decreases blood pressure when standing

Respiratory Effects
 Acute
use causes bronchodilation
 Chronic use leads to:
 Bronchitis,
asthma
 Tar from smoking is more carcinogenic than tobacco tar

Causes reddening of the eyes
Side Effects, cont.

Causes decreased intraocular pressure
 Used



for glaucoma
Can cause decreased testosterone levels and
reduced sperm formation in males
If smoked during pregnancy, it can lead to low birth
weight, longer labors and increased risk for infant
malformations
Studies in animals have shown decreased immune
response, but correlation to humans is still unknown
Long-term effects

These side effects can last much longer than the
“high”
 THC
is not eliminated from the body right away because
it is stored in fat tissue and is therefore not available for
the body to remove from the bloodstream
 This can affect motor skills necessary for driving
Questions?