Lecture 7- Psychomotor Stimulants I: Amphetamines And Cocaine Flashcards
Psychomotor stimulants do what
-Psycho: stimulate alertness, arousal
-Motor: stimulate motor activity
Amphetamines have a similar structure to
Catecholamines (dopamine, norepinephrine, epinephrine)
What’s the base structure of amphetamines
Phenylethylamine
Naturally occurring amphetamines
-Cathinone
-Ephedrine/ pseudoephedrine
Effects of cathinone
-Increased heart rate
-Excitement
-Euphoria
-Decreased appetite
-Potent stimulant
Effects of ephedrine
-Constricts nasal blood vessels
-Cold treatment
Amphetamines have a racemic (1:1) mixture of
-d- and l-isomer
-Can be called amphetamines even if not 1:1
What is d-amphetamine
Dextroamphetamine
What is L-amphetamine
-Levoamphetamine
-Less potent
Methamphetamines were first synthesised by
Akira Ogata in Japan (1919)
What is pseudoephedrine (PE)
Precursor to meth
What is appetrol
-Amphetamine
-Used for weight loss
-Only a small amount maintained weight control
Most ADHD and ADD drugs are
Psychomotor stimulants
Amphetamines elimination half life is
10 hours
Amphetamines have what autonomic functions in humans
-Increased blood pressure
-Hyperthermia
-Bronchodilation
What are the withdrawal effects of amphetamines
-Increased fatigue
-Anxiety
-Depressed mood
-Craving that can last for days
Major effects of amphetamines
-Analeptic
-Anorexia
-Decreased fatigue, increased alertness
-Euphoria
-Amphetamine psychosis
What are the psychomotor stimulant effects of amphetamines in non humans
-Complex dose-effect relations
-Low doses-locomotor hyperactivity
-Higher doses-stereotyped behaviour
Do non-humans have the same autonomic functions as humans
Yes
Unconditioned effects of amphetamines in non humans
-Lower dose produces more naturalistic behaviours
-Increasing dose cause naturalistic behaviours to become repetitive ’mindless’ fragmented stereotypes
Features of alkaloid in leaves of erythroxylon coca
-Reduces altitude sickness
-Reduces hunger and increases energy
-Taken as tea
-Naturally occurring insecticide
Forms of cocaine
-Raw leaves
-Cocaine paste
-Cocaine hydrochloride
-Crack
-Cocaine free base
-Cocaine with other ingredients
Features of cocaine in the form of raw leaves
-Alkaloid content low
-Absorbed in the mucous membranes of the mouth
-Eat with lime to increase pH of the saliva, release more active ingredient
-Low addictive potential
-Does not produce a high
Features of cocaine paste
-Made in pit ‘pozo’
-20-80% cocaine sulphate
-100kg of leaves= 1kg of paste
-Cheap, low grade smokable cocaine
Method of cocaine paste
-Cocaine alkaloids are mixed with dilute sulphuric acid
-Followed by sodium carbonate
Features of cocaine hydrochloride
-Usually snorted or injected
-Snorted results in 20-30% entering the bloodstream
-Inefficient to smoke since vaporisation temp is close to burn temp
-Street cocaine is often cut with mannitol
Method of cocaine hydrochloride (salt form)
-Cocaine paste is further processed with potassium permanganate
-Acetone/ether added
-Hydrochloric acid and crystalline powder is extracted
Features of cocaine free base
-Prepared by adding water and base (e.g ammonia) and mixing with ether
-Low melting point (90c)
-Can be vaporised and smoked
Features of crack
-Crude preparation of free base
-75-90% pure
-Reaches the brain within seconds
-Finished by 5-15 mins
Similarities between cocaine and
Amphetamines with
-behavioural effects
-subjective effects from users
-Difficulty discriminating between the two
What is cocaines half life
-Between 0.5 to 1.5 hours
-Rapid metabolism and elimination
Duration of action in amphetamines
7-30 hours
Differences between cocaine and amphetamines
-Cocaine is a local anaesthetic, inhibits Na+ channels
-Cocaine can cause a stroke, convulsive properties
Effects of repeated psychostimulant administration
-Typically tolerance effects: autonomic effects, anorectic effect, euphorigenic
-Escalation of dose to achieve similar effects
Tolerance is likely to occur with
-Closely spaced drug exposure
-Continuous infusion of drug
-Binge usage
Examples of punding
-Non-goal directed, socially meaningless activities:
-Repetitious picking
-Collecting
-Assembling/ disassembling
Increased YMRS activity after
2nd amphetamine dose
Factors that influence sensitisation
-Stress
-Sex
-Rate of infusion
-Environment
Repeated cocaine increases what in mice
Distance travelled compared to saline
