The document discusses central nervous system (CNS) stimulants. It defines stimulants as substances that increase behavioral activity when administered. CNS stimulants can elevate mood, increase motor activity and alertness, and decrease need for sleep. The mechanisms of action of stimulants include blocking neurotransmitter reuptake, promoting neurotransmitter release, and blocking metabolism or antagonizing inhibitory neurotransmitters. Specific stimulants discussed include amphetamine, picrotoxin, and strychnine, along with their mechanisms and effects on mice.

1. PHL. 322PHL. 322
Presented byPresented by
Dr. Khairy M A ZoheirDr. Khairy M A Zoheir
Associate ProfessorAssociate Professor
College of PharmacyCollege of Pharmacy
KSUKSU

2. I- CNS Stimulants DrugsI- CNS Stimulants Drugs

3.
Nervous SystemNervous System
• The nervous system can be classified intoThe nervous system can be classified into
• The Central Nervous SystemThe Central Nervous System ((CNS)CNS)
Brain and spinal cordBrain and spinal cord
• The Peripheral Nervous SystemThe Peripheral Nervous System
((PNSPNS(( The nervous system outside of theThe nervous system outside of the
brain and spinal cordbrain and spinal cord

4.
Peripheral Nervous System PNSPeripheral Nervous System PNS
Can be divided intoCan be divided into- -
11--Sensory divisionSensory division ((affrentaffrent((
Conducts impulses from receptors to theConducts impulses from receptors to the
CNS and Informs the CNS of the state ofCNS and Informs the CNS of the state of
the bodythe body
2-2- Motor divisionMotor division((effrent)effrent)
Conducts impulses from CNS to effectorsConducts impulses from CNS to effectors
organsorgans..

5.
Motor NeuronsMotor Neurons
• The motor division is also divided intoThe motor division is also divided into
• 1-1- The somatic nervous system :The somatic nervous system :
•VOLUNTARY (generally) Somatic nerve fibersVOLUNTARY (generally) Somatic nerve fibers
that conduct impulses from the CNS to skeletalthat conduct impulses from the CNS to skeletal
musclesmuscles
• 2.2. The autonomic nervous system:The autonomic nervous system:
INVOLUNTARYINVOLUNTARY ((generallygenerally)) Conducts impulsesConducts impulses
from the CNS to smooth muscle, cardiacfrom the CNS to smooth muscle, cardiac
muscle, and glands muscle, and glands

6. NeuronsNeurons
• They are the basic functional unit of theThey are the basic functional unit of the
nervous systemnervous system..
• They contain three major partsThey contain three major parts::
• 1.cell body.1.cell body.
• 2. dendrites.2. dendrites.
• 3. axon. 3. axon.

7. StructureStructure

8. Neurotransmitters CNSNeurotransmitters CNS
• They can be classified intoThey can be classified into ::
• 1.1. Exitatory:Exitatory:
• - Ach, glutamate, aspartate , serotonin and- Ach, glutamate, aspartate , serotonin and
NE. NE.
• 22. Inhibitory:-. Inhibitory:-
• - GABA , glycin .- GABA , glycin .

9. CNS StimulantsCNS Stimulants
• DefinationDefination
““Stimulants are a substance whichStimulants are a substance which
tends to increase behavioraltends to increase behavioral
activity when administered”activity when administered”

10. • Signs and symptoms:Signs and symptoms:
• 1- Elevate Mood1- Elevate Mood
• 2- Increase Motor Activity2- Increase Motor Activity
• 3- Increase Alertness3- Increase Alertness
• 4- Decrease need for Sleep4- Decrease need for Sleep
• In case of overdose lead to convulsionIn case of overdose lead to convulsion
and death.and death.

11. MOA of CNS StimulantsMOA of CNS Stimulants
• 1- Block neurotransmitters reuptake (Most1- Block neurotransmitters reuptake (Most
reuptake inhibitors affect either NE or 5-reuptake inhibitors affect either NE or 5-
HT(Serotonin) : CocaineHT(Serotonin) : Cocaine
• 2- Promote neurotransmitters release :2- Promote neurotransmitters release :
AmphetamineAmphetamine
• 3- Block Metabolism - MAO inhibitors3- Block Metabolism - MAO inhibitors
(monoamine oxidase):ex. Phenelzine(monoamine oxidase):ex. Phenelzine
• 4. antagonize the effect of inhibitory4. antagonize the effect of inhibitory
neurotransmitter:neurotransmitter: PicrotoxinPicrotoxin && StrychnineStrychnine
•

12. Neuronal SynapseNeuronal Synapse

13. Neuronal SynapseNeuronal Synapse

14. CNS StimulantsCNS Stimulants
• -- They can be divided based on their siteThey can be divided based on their site
of actionof action::
• 1.Cerebral stimulants (amphetamines) 1.Cerebral stimulants (amphetamines)
• 2.Medullary stimulants (picrotoxin) 2.Medullary stimulants (picrotoxin)
• 3.Spinal stimulants (strychnine)3.Spinal stimulants (strychnine)

15. Lab WorkLab Work
• -- Objectives:Objectives:
• 1- To demonstrate effects of some CNS1- To demonstrate effects of some CNS
stimulant on mice.stimulant on mice.
• 2- After the lab, you should able to handle and2- After the lab, you should able to handle and
inject the mice correctly.inject the mice correctly.
• 3- You should able to differentiate between3- You should able to differentiate between
amphetamine,picrotoxin and strychinineamphetamine,picrotoxin and strychinine
regarding the symptoms that induced by each ofregarding the symptoms that induced by each of
them. them.

16. 1- Amphetamine 1- Amphetamine
• MOAsMOAs ::
• Block the reuptake of norepinephrine andBlock the reuptake of norepinephrine and
dopamine into the presynaptic neuron anddopamine into the presynaptic neuron and
increase the release of these monoamines intoincrease the release of these monoamines into
the extraneuronal space. the extraneuronal space.
- Clinical use:- Clinical use:
• 1. Narcolepsy.1. Narcolepsy.
• 2. Attention-deficit hyperactivity disorder2. Attention-deficit hyperactivity disorder

17. AmphetamineAmphetamine
• Adverse effectsAdverse effects::
• - Cardiovascular:- Cardiovascular: Hypertension (7% to 22%, pediatricHypertension (7% to 22%, pediatric
))
• - Endocrine metabolic:- Endocrine metabolic: Weight loss (4% to 9%,Weight loss (4% to 9%,
pediatric; 11%, adults )pediatric; 11%, adults )
• - Gastrointestinal:- Gastrointestinal: Abdominal pain (11% to 14%,Abdominal pain (11% to 14%,
pediatrics ), Loss of appetite (22% to 36%), Xerostomiapediatrics ), Loss of appetite (22% to 36%), Xerostomia
(35% )(35% )
• - Neurologic:- Neurologic: Headache (26% ), InsomniaHeadache (26% ), Insomnia ))1212 % to% to
17%, pediatric; 27%, adults )17%, pediatric; 27%, adults )
• - Psychiatric:- Psychiatric: Feeling nervous (6% ) Feeling nervous (6% )

18. AmphetamineAmphetamine
• After injecting, the mice withAfter injecting, the mice with
amphetamine you well noticeamphetamine you well notice::
- Hair erection- Hair erection
• - Licking, gnawing.- Licking, gnawing.
• - Stereotype- Stereotype
• - Sniffing - Sniffing

19. PicrotoxinPicrotoxin
• MOAMOA::
• Non-competitive antagonist of GABA receptors.Non-competitive antagonist of GABA receptors.
• After injecting the mice with picrotoxin youAfter injecting the mice with picrotoxin you
well noticewell notice::
-- Clonic convulsionClonic convulsion characterized by : characterized by :
• 1. Asymmetric1. Asymmetric
• 2. Intermittent2. Intermittent
• 3. Spontaneous3. Spontaneous
• 4. Coordinated4. Coordinated

20. StrychinineStrychinine
• MOAMOA::
• Competitive antagonist of the glycin receptors. Competitive antagonist of the glycin receptors.
• After injecting the mice with Strychinine you wellAfter injecting the mice with Strychinine you well
• notice: notice:
-- Tonic convulsionTonic convulsion characterizedcharacterized by :by :
• 1. Symmetric1. Symmetric
• 2. Reflex in origin2. Reflex in origin
• 3. Continuous3. Continuous
• 4. Uncoordinated.4. Uncoordinated.