Download CNS Stimulants Drugs

PHL. 322
Presented by
Dr. Khairy M A Zoheir
I- CNS Stimulants Drugs
Nervous System
• The nervous system can be classified into
• The Central Nervous System (CNS)
Brain and spinal cord
• The Peripheral Nervous System
(PNS (The nervous system outside of the
brain and spinal cord
Peripheral Nervous System PNS
Can be divided into1- Sensory division(affrent)
Conducts impulses from receptors to the
CNS and Informs the CNS of the state of
the body
2- Motor division(effrent)
Conducts impulses from CNS to effectors
organs.
Motor Neurons
• The motor division is also divided into
• 1- The somatic nervous system :
VOLUNTARY (generally) Somatic nerve fibers •
that conduct impulses from the CNS to skeletal
muscles
• 2. The autonomic nervous system:
INVOLUNTARY (generally) Conducts impulses
from the CNS to smooth muscle, cardiac muscle,
and glands
Neurons
• They are the basic functional unit of the
nervous system.
• They contain three major parts:
• 1.cell body.
• 2. dendrites.
• 3. axon.
Structure
Neurotransmitters CNS
• They can be classified into :
• 1. Exitatory:
• - Ach, glutamate, aspartate , serotonin
and NE.
• 2. Inhibitory:• - GABA , glycin .
CNS Stimulants
• Defination
“Stimulants are a substance which
tends to increase behavioral
activity when administered”
• Signs and symptoms:
• 1- Elevate Mood
• 2- Increase Motor Activity
• 3- Increase Alertness
• 4- Decrease need for Sleep
• In case of overdose lead to convulsion and
death.
MOA of CNS Stimulants
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1- Block neurotransmitters reuptake (Most
reuptake inhibitors affect either NE or 5HT(Serotonin) : Cocaine
2- Promote neurotransmitters release :
Amphetamine
3- Block Metabolism - MAO inhibitors
(monoamine oxidase):ex. Phenelzine
4. antagonize the effect of inhibitory
neurotransmitter: Picrotoxin & Strychnine
Neuronal Synapse
Neuronal Synapse
CNS Stimulants
• - They can be divided based on their site
of action:
•
1.Cerebral stimulants (amphetamines)
•
2.Medullary stimulants (picrotoxin)
•
3.Spinal stimulants (strychnine)
Lab Work
• - Objectives:
• 1- To demonstrate effects of some CNS
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stimulant on mice.
2- After the lab, you should able to handle and
inject the mice correctly.
3- You should able to differentiate between
amphetamine,picrotoxin and strychinine
regarding the symptoms that induced by each of
them.
1- Amphetamine
• MOAs :
• Block the reuptake of norepinephrine and
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dopamine into the presynaptic neuron and
increase the release of these monoamines into
the extraneuronal space.
- Clinical use:
1. Narcolepsy.
2. Attention-deficit hyperactivity disorder
Amphetamine
• Adverse effects:
• - Cardiovascular: Hypertension (7% to 22%, pediatric
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)
- Endocrine metabolic: Weight loss (4% to 9%,
pediatric; 11%, adults )
- Gastrointestinal: Abdominal pain (11% to 14%,
pediatrics ), Loss of appetite (22% to 36%), Xerostomia
(35% )
- Neurologic: Headache (26% ), Insomnia ‫( ارق‬12% to
17%, pediatric; 27%, adults )
- Psychiatric: Feeling nervous (6% )
Amphetamine
• After injecting, the mice with
amphetamine you well notice:
- Hair erection
• - Licking, gnawing.
• - Stereotype
• - Sniffing
Picrotoxin
• MOA:
• Non-competitive antagonist of GABA receptors.
• After injecting the mice with picrotoxin you
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well notice:
- Clonic convulsion characterized by :
1. Asymmetric
2. Intermittent
3. Spontaneous
4. Coordinated
Strychinine
• MOA:
• Competitive antagonist of the glycin receptors.
• After injecting the mice with Strychinine you well
• notice:
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- Tonic convulsion characterized by :
1. Symmetric
2. Reflex in origin
3. Continuous
4. Uncoordinated.