The document discusses various drugs including cocaine, opiates, and marijuana. It provides information on their mechanisms of action in the brain and possible signs and symptoms of use. It also describes a case study of a 33-year-old man found unconscious who was given dextrose and naloxone by paramedics and showed improved vital signs at the hospital. Based on his symptoms, it is suspected he had used cocaine or opiates. The document discusses how these drugs act on the brain's reward pathway similarly to stimulate dopamine and cause addiction.

1. The Brain & Drugs
Including the actions of Cocaine,
Opiates, and Marijuana

2. Objectives
1. Understand the basic geography of the brain and its
relationship to function.
2. Know the anatomy and function of the neuron.
3. Understand the chemical synapse including the basic
mechanism of nervous communication.
4. Know the function, components and location of the
reward pathway.
5. Understand the signs and symptoms of use and the
mechanism of action of cocaine, opiates and THC.
6. Apply knowledge to a case study.

4. Case Study – Part 1a
• Parents of a 33 year old man called 911 after finding their son
lying unresponsive on the floor of the basement
• The parents report he is a drug addict and may have used
earlier
• Paramedics arrive and get the following vital signs:
– BP: 124/80
– Pulse: 104
– Respirations: 10, shallow
– Pupils: constricted and non‐reactive
– Skin: cool and cyanotic (blue)
– Glucose: 55 mg/dL
• Are these vital signs normal?
• Are there any other questions you would ask or observations
you should make before you take the patient to the hospital?

5. Case Study – Part 1b
• BP: 124/80 – prehypertensive but not an emergency
• Pulse: 104 – slightly tachycardic
• Respirations: 10, shallow – hypoventilating
• Pupils: constricted and non‐reactive ‐ abnormal
• Skin: cool and cyanotic (blue) ‐ abnormal
• Glucose: 55mg/dL – hypoglycemic
– We did not cover this, but 70‐180 for non‐fasting glucose is
normal
• There are many possible questions or observations but you
should be trying to figure out what he took. Do the parents
know? Is there any of it lying around the room?
• There is a tourniquet and a needle in the room.

6. The Brain
• The brain is the center of the
nervous system
• Cells in the brain are grouped into
neurons and glia
– Neurons are the functional units
– Glia is a term for a broad class of
supporting cells
• The lobes of the brain: Frontal,
Parietal, Occipital, and Temporal
• Neurons are connected by
synapses which allow them to
communicate with each other

7. The Neuron
• Dendrites and soma (cell
body) receive chemical
information from neighboring
neuronal axons
• The chemical information is
converted to electrical
currents which travel toward
and converge on the soma
• A major impulse is produced
(the action potential) and
travels down the axon toward
the terminal.

8. The Synapse and Synaptic Neurotransmission
• The action potential traveling down the axon starts a series of events at
the terminal that results in vesicles containing a neurotransmitter, such as
dopamine (the stars), to become exocytosed into the synaptic cleft.
• Once inside the synaptic cleft, the dopamine can bind to specific proteins
called dopamine receptors (in blue) on the membrane of a neighboring
neuron
• Occupation of receptors by
neurotransmitters causes various
actions in the cell
• activation or inhibition of enzymes
• entry or exit of certain ions
• These actions can be excitatory
or inhibitory

9. Reuptake
• Neurotransmitters (NTs) in the synaptic cleft are removed by:
– Enzymatic degradation
– Reuptake by specific proteins (in purple) to return the NT to presynaptic terminal
– Diffusion
• Removing the NT is important to prevent constant stimulation of the
receptor

10. • Synaptic clefts
Neuromodulation sometimes include
more than two neurons
that allow for
neuromodulators, such
as endorphin (gray), to
act on the same neuron
• Neuromodulators act
on a different receptor,
opiate in this case,
which adds another
signal to the
postsynaptic
membrane
• The sum of all the
signals determines
what occurs in the next
neuron

11. The Reward Pathway
• There are pathways in the brain that
have been identified for specific
functions such as sight, movement or
reward.
• The reward pathway is activated by a
rewarding stimulus such as food,
water, sex and some drugs.
• Reward Pathway Components (In
order):
– Ventral Tegmental Area (VTA)
– Nucleus Accumbens
– Pre‐Frontal Cortex
• This pathway and many others were
identified by placing probes into rat
brains

12. Case Study – Part IIa
• En route to the hospital, the paramedics give dextrose and 5.2mg of
Narcan
– Why give dextrose?
– We will discuss Narcan later.
• When the patient arrives at the hospital, he is alert and responsive,
new vital signs:
– BP: 117/88
– Pulse: 111
– Respirations: 24
– Pupils: not observed
– Skin: 97.4 °F
– Glucose: 120 mg/dL
• Classify these vital signs.
• At this point, what do you think the patient took?

13. Case Study – Part IIb
• Dextrose given to raise blood sugar
• BP: 117/88 ‐ prehypertensive
• Pulse: 111 ‐ tachycardia
• Respirations: 24 ‐ hyperventilating
• Pupils: not observed
• Skin: 97.4 ‐ normal
• Glucose: 120 mg/dL – normal
• Place your bets on what he took, we will review some
drugs now

14. Cocaine Possible presenting
signs and symptoms:
• A central nervous system   body temperature
stimulant   blood pressure
  heart rate
• Can be snorted, injected or  confusion
smoked  paranoia
 dilated pupils
• Is the active ingredient in crack  irritability
• Gives a euphoric and energetic  scratching
 hallucinations
feeling  short temperament
• Risks: Heart attack, respiratory  Anxiety/panic attacks
 Sleeplessness
failure, strokes, seizures,  Loss of appetite
abdominal pain, nausea, death   sex drive
 Very talkative
• 2009: 4.8 million Americans 12
or older had abused cocaine

15. Mechanism of Action Of Cocaine
• Cocaine (teal) localizes in the reward
pathway of the brain and mimics
dopamine
• Cocaine blocks reuptake of dopamine,
leaving more dopamine in the synapse
and causing more receptors to be
activated
• Increased activation of the dopamine
receptor results in an abnormally high
firing rate in the post synaptic
terminal
• The reward pathway is maximized and
addiction results from prolonged use
and the inability to reproduce cocaine
affect without the drug

16. Localization of
Cocaine

17. Opiates Possible presenting
signs and symptoms:
• A class of drugs that share a similar
chemical structure originally obtained as  Fade in and out
natural products of the opium poppy plant wakefulness
• Includes: heroin, morphine, fentanyl,  Flushing of skin
oxycodone, methadone, codeine  Dry mouth
• Many routes of administration, injection is  Slowed breathing
common  Constricted pupils
 “Heavy” extremities
• Creates a feeling of euphoria and  Nod off suddenly
relaxation – a depressant  Unclear thinking
• The major risk is depression of breathing  Itching
possibly resulting in death  Vomiting
• Mixing opiates together or with stimulants  Nausea
(cocaine) greatly increases the dangers of  Constipation
abuse
• Overdose should be immediately treated
with an opiate antagonist

18. Mechanism of Action of Opiates
• Opiates act in the dopamine synaptic cleft with three neurons
• Opiates activate the opiate receptor causing more dopamine to be
released into the synaptic cleft
• Opiates, like cocaine over stimulate the reward pathway causing
addiction

19. Marijuana and THC
• Marijuana is dried up parts of
the Cannabis sativa hemp plant Possible presenting
• THC is the active ingredient, signs and symptoms:
delta‐9‐tetrahydrocannabinol
• Method of abuse is usually  Bloodshot eyes
smoking  Compulsive eating
 Squinty eyes that may be
• It gives a euphoric feeling, difficult to keep open
distorted perceptions, memory  Dry mouth
impairment and difficulty  Forgetfulness
solving problems  Uncontrollable laughter
 Short‐term memory loss
• It is the most commonly used  Lethargy
illegal drug in the US  Delayed motor skills
 Paranoia
 Hallucinations

20. THC and the Brain
• THC acts with a similar
mechanism to opiates
• THC binds to THC receptors in
the following areas:
– Reward Pathway (VTA, NA) ‐
Pleasure
– Hippocampus – Affecting memory
– Cerebellum – Loss of coordination
and balance

21. The Reward Pathway and Drugs
• The reward pathway is only one area that
each drug acts
• It is what makes the user feel good and can be
involved in the addiction process
• Each drug acts on other areas as well, which is
why each can have different affects such as
stimulating or depressing

22. Prescription Drug Abuse
• Defined as taking a prescription medication that is not
prescribed to you or taking it for reasons or dosages
other than prescribed
• Different classes and varieties that are abused include:
– Opiods – Vicodin, Oxycontin, Darvon, Dilaudid, Demerol,
Lomotil
– Depressants – barbituates, benzodiazepines (Valium,
Xanex)
– Stimulants – Ritalin, Concerta, Adderall
• It a serious and growing problem
– About 20% of people in the US have used prescription
meds for nonmedical reasons
– Prescription drug abuse now exceeds illicit drug abuse
worldwide

23. Case Study – Part 3a
• What drug do you think the patient took?
• What do you think Narcan is?

24. Case Study – Part IIIb
• Narcan is a brand name for naloxone, an opiate
antagonist, given for opiate overdoses
• The patient says he took too much heroin.
• Urine toxicology is positive for opiates and cocaine.
• The patient is evaluated by a physician and reports he
has normal neurologic function and normal mentation.
• Three hours after getting to the hospital a nurse
reports decreased lung sounds on both sides.
• Five hours after getting to the hospital his vital signs
have returned to normal.
• The ED and the waiting room are full. What should you
do? Discharge, admit or keep in the ED?

25. Case Study – Part IIIc
• The attending physician decides to discharge
the patient to his parents.
• Five hours after discharge, the patient is once
again found unresponsive in his bed.
• Paramedics arrive, find him in asystole,
attempt resuscitation but have no success
• Patient is pronounced dead at the scene
• How could this have been prevented?

26. Case Study – Part IIId
• Presence of cocaine in the urine should have
tipped the physician off that there was more to
the story.
• Decreased breath sounds was another clue that
should have prompted further evaluation.
• Cocaine can cause pulmonary edema and
myocardial infarctions, which is what occurred in
this patient.
• The physician did not follow the standards of care
for this situation.

27. This is your brain on drugs…
Any Questions?