SUBSTANE OF ABUSE 414 PHG CNS stimulants
Jan 03, 2016
• Identify the different classes of CNS stimulants
• Determine pharmacological actions of CNS stimulants.
• Evaluate dependence liability and types of CNS stimulant drugs.
• Build an addiction treatment plan of CNS stimulants.
Learning outcomes
1. Amphetamine–Methamphetamine–Ritaline
2. Cocaine3. Nicotine4. Ephedra5. Khat6. Coca7. Tobaco
CNS stimulants topics
• The main effects are: – increased motor activity – euphoria and excitement – anorexia – with prolonged administration, stereotyped
and psychotic behavior.
Amphetamine
• Effects result mainly from release of catecholamines, especially noradrenaline and dopamine
• Stimulant effect lasts for a few hours and is followed by depression and anxiety
1- Amphetamine
• Tolerance to the stimulant effects develops rapidly, (peripheral sympathomimetic effects may persist).
• Amphetamines may be useful in treating narcolepsy and also (paradoxically) to control hyperkinetic children.
• No longer used as appetite suppressants (risk of pulmonary hypertension) .
Amphetamine
• Amphetamine psychosis, which closely resembles schizophrenia, can develop after prolonged use.
• Their main importance is in drug abuse.
Amphetamine
Methamphetamines
Most abused form of amphetamines
Methamphetamine is generally a white or off-white powder that can be ingested in several ways:
• Orally
• Snorted
• Injected
• Smoked
Short Term Side Effects
• Excessive Talking
• Increased Activity
• Nervousness
• Decreased Fatigue
• Anxiety / Panic Attacks
• Hallucinations
• Nervousness
• Excessive Sweating
• Skin Welts
• Violent / Suicidal Behavior
Long Term Side Effects
Methamphetamine use can cause serious long term side effects that can affect the user for the rest of their life:
• Immune System Damage
• Psychological Problems
• Severe Brain Damage
• Fatal Kidney Disorders• Fatal Lung Disorders• Birth Defects• Stroke• Death
Ritalin(methylphenidate)
• Prescribed to ADD and ADHD patients under the brand names, Ritalin, and Aderall.
• ADD /ADHD is thought to be caused by under functioning of the parts of the brain associated with impulse control and executive functions.
• The stimulant nature of aderall, ritalin, etc. speed up the neural transmission to a “normal” level of function
Historical Overview
• Indigenous Peruvians once considered the coca plant to be divine
• They named it “khoka” which means “the plant”• Europeans changed the name to “coca”• 1859-1860, German scientist,Albert Niemann,
isolated and named cocaine.• 1856, Samuel Percy was the first to suggest that
coca leaves could be used as an anesthetic• 1884 used in clinical practice
Chewing: with an-alkaloid material (South America)Sniffing: hydrochloride salt -absorption: nasal mucous membranes –local vasoconstriction slows absorption and prolongs effect
Routes of Administration:
Oral: large doses are needed for effect rapid onsetSmoking: cocaine is converted to alkaloid (freebase or "crack") which is readily volatilized undegraded at lower temperature. I.V. and smoking: reaches CNS in seconds in high concentration produces more immediate and intense effects.
Routes of Administration:
Effects of Cocaine
Rapid and intensely euphoric sensation commonly called a “rush”Increased heart rateChest painCardiac arrestTremorsBreathing irregularitiesHyperthermia
Intense sweatingPanicAgitationParanoiaHallucinationsDeliriumSeizures
Cocaine Toxicity
Chest painHypertensionTachycardiaMyocardial ischemia and/or infarctionPulmonary edemaAortic rupture
Cardiac dysrhythmiaHemorrhagic strokeEndocarditisMyocarditisCardiomyopathySudden death
Street Names continued…
The crystal form of cocaine is also known as: • Crack • Base • Free base • French fries • Ready rock • Rock
Nicotine (tobacco) Second after caffeine as the most widely used
CNS stimulant Second after alcohol as the most abused drug.
CNS Effects: Lower doses produce: Powerful CNS stimulant Large doses produce : convulsion, then depress CNS, Stimulates respiration, Produces
emesis . Tolerance to central actions with chronic use
3- Nicotine
Nicotine causes excitation followed by inhibition of all synaptic and parasynaptic ganglia.
At low doses → ganglionic stimulation by depolarization of the postganglionic membrane.
At high doses →ganglionic blockade
Mode of Action
TachycardiaIncreased blood pressureGanglionic blockade and arrhythmias Fatalities: Due to respiratory failure
Cardiovascular effects
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• Nicotine is an addictive substance and produce both physical & psychological dependence.
• Withdrawal from nicotine "quite smoking" → irritability, anxiety, restlessness, difficulty in concentration, headache, insomnia, increase appetite and GIT pain.
• Withdrawal symptoms ↓ by: tans dermal patches
Toxicity
Ephedrine
Norpseudoephedrine (Cathine)
•Common names: Ma Huang; Brigham tea;
Natural Ecstasy…etc.
•Scientific name: Ephedra sinica and other spp.
•Part used: The stems
•Active constituents: Alkaloids (0.5-2.5%),
ephedrine:major one (pseudoepherdrine,
norephedrine, …others).
Ephedra
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Ephedrine is structurally related to
amphetamine and causes CNS stimulation in a
similar way to amphetamines through
increasing the availability of endogenous
neurotransmitters.
Dosage: quantity of ephedra equivalent to
24mg ephedrine/day.
Preparation: Crude powdered drug,
tinctures; fluid extr.
Actions and uses
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•Contraindications and precautions:
• In pregnancy → risk of uterine stimulation
• In diabetic patients → hypoglycemic effects.
• In patients with cardiac arrhythmias, angina,
with history of cerebral disease.
•Concomitant use with beta blockers and
MAO inhibitors →risk of GI and CNS
adverse effects
Actions and uses
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Cathinone
•Scientific name: Catha edulis Forsk. (Fam.
Celastraceae).•Part used: Fresh leaves and twigs.
•Constituents: •Cathinone1%, Norepseudoephedrine;
•Ephedrine…etc.•Tannins, vol. oil.
Khat
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Actions and uses:
The CNS stimulation of khat is manly due to
cathinone and norepseudoephedrine.
(It shows amphetamine –like actions).
Khat is manly used as a social drug through
chewing or taken as an infusion.
Khat is used in Germany to counter obesity.
Cathinone
Khat
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•Scientific name: Erythroxylom coca, and other e. spp, (Fam. Erythroxylaceae)
•Part used: The leaves.•Constituents: •Alkaloids cocaine (0.7-1.5%), together with
cinnamyl cocaine, and α- and β- truxillines.•Vol. oil, Flavonoids, Tannins, Vit. A and B2 and
minerals.
Coca
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Nicotine
•Scientific name: Nicotiana tabaccum (Fam. Solanaceae).
•The Part used: The leaves.•Constituents: Alkaloids (nicotine is the most important)
•Actions and Uses:• It is a psychomotor CNS stimulant (some degree
of euphoria, and arousal, as well as relaxation, and improves learning, problem solving and reaction time).
Tobaco
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Nicotine
It is grown mainly produce smoking or smokeless tobacco.Dried leaves make a good insecticide.It is no longer used medicinally.
Smokeless tobacco:Prepared from the same botanical source,
and usually flavored with sugar or artificial sweeteners.
Tobaco
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Which is more toxic in terms of health and economic expenses, tobacco, khat or Coffe and tea
Activity 2
1- Compare the behavioral effects and toxicity of coca, ephedra and khat.2- How amphetamine and cocaine addiction can be treated?3- Explain the different treatment approaches for the amohetamine and cocaine toxicities.
Review questions