Stimulants and Alcohol Flashcards
How to take cocaine
Typically snorted in powder form or smoked in its free-base form (crack)
Cocaine in blood and half life
Reaches peak in blood at 30-60 minutes
Easily penetrates the blood-brain barrier
Biological Half Life: 30-90 minutes
Cocaine Short Term Effects
- Euphoria
- Energy
- Confidence
- Talkativeness
- Activity
- Alertness
- Attention
Neurons with cocaine
Cocaine acts on mono-aminergic synapses in the brain (serotonin, dopamine, noradrenaline, adrenalin)
Cocaine blocks the reuptake channel of the mono-aminergic synapses, making the synapse effect stronger.
Also associated with the wake side of the sleep wake cycle - why people on cocaine can’t sleep.
Cocaine Long Term Effects - Depression
Lack of reuptake results in depletion of monoamines (serotonin, noradrenaline etc) so there is a depression crash that is remedied by taking more cocaine
Nasal Septum vs Cocaine
This is because of vasoconstriction.
Cocaine Long Term Effects - Schizophrenic-like symptoms
Hallucinations
Delusions of persecution
Mood disturbances
Repetitive Behaviours
More Cocaine Long Term Effects
Sexual dysfunction
Tolerance for some of the ‘desired’ effects, such as euphoria and confidence
Sensitisation or other effects, such as convulsiveness, stereotyped behaviour, addictiveness
Cocaine Addictiveness
Direct effect on dopamine released in the nucleus accembens and prefrontal cortex
Direct activation of the ‘seeking’ or ‘reward’ pathway
Strong psychological addictiveness, much less physical addictiveness
Types of amphetamines
Speed - taken orally
Crystal Meth - smoked
Ecstacy - taken orally
Mephedrone/Methadrone/Methylone - snorted or orally
Amphetamines half life and blood-brain barrier
Uptake speed and half-life depend on the drug and method of taking it
All cross through blood-brain barrier with ease
Amphetamines short term effects
- Euphoria
- Energy
- Confidence
- Talkativeness
- Activity
- Alertness
- Attention
Ecstacy short term effects
Increased confidence and feelings of energy lead to an increase in dehydration, exhaustion, muscle breakdown, overheating and convulsions
Amphetamines long term effects
Similar to cocaine: hallucinations, delusions of persecution, mood disturbances, repetitive behaviour.
You also get a tolerance to some effects and a sensitisation to others
Extended use can kill dopaminergic and serotonergic neurons in the brain
Amphetamines addictiveness
Like cocaine there is strong potential for psychological addiction but not much for physical addiction
How does Ritalin work?
Acts similarly to cocaine by blocking the monoamine reuptake transporter. The release is much more gradual and does not have the immediate effects cocaine does.
Caffeine
Typically ingested in coffee or soft drinks
Concentration peaks after 40 minutes
Easily passes through blood-brain barrier
Half life of 3.5-5 hours and even longer in children
Lethal dose is 100 cups of coffee/10g of caffeine
Caffeine’s Short Term Effects
Increases alertness and wakefulness Induces clear thinking Induces restlessness Difficulty with fine movements Increases cardiac contractions Constricts blood vessels
Caffeine Side Effects
Anxiety
Insomnia
Change in mood
Hypertension
How does caffeine work?
Blocks adenosine receptors
Adenosine is involved in inducing sleep and vasodilation
Stimulates adrenaline release from adrenal medulla
Caffeine long term effects
Mostly sleep deprivation (especially slow wave sleep), can be countered with more caffeine.
Caffeine Addictiveness
Clear physical dependence with withdrawal symptoms including headaches, sleepiness, irritability and difficulty concentrating
Psychological dependence: increases dopamine in nucleus accumbens
How to take nicotine
Usually smoked but sometimes chewed
Nicotine vs blood-brain barrier
Within 7 seconds of the puff, 25% of the nicotine in the smoke has already crossed the blood-brain barrier
Nicotine half-life
2 hours in the chronic smoker
Nicotine short-term effects
Induces vomiting
Reduces muscle tone (relaxes)
Reduces weight gain
Increases heart rate and blood pressure
How does nicotine work?
Binds to nicotinic acetylcholine receptors found in the brain. These receptors are involved in stimulation of the sympathetic nervous system, including the release of adrenaline from the adrenal gland.
Nicotine long term effects
Body easily builds tolerance and possibly wears out the heart quicker.
Major problems associated with tobacco and smoke that can cause cancer, cardiovascular disease and more
Nicotine Addictiveness
Withdrawal symptoms include craving, irritability, increased appetite and insomnia.
Could be the most addictive drug psychologically
How is alcohol taken?
Usually ingested, easily crosses the blood brain-barrier and reached max blood concentration in 30-90 minutes.
Mostly eliminated through the liver, which breaks it down at a steady rate
Alcohol short term effects - low dose
In a low dose there’s mild euphoria and it lowers anxiety
Also produces dilated blood vessels and more urination
Alcohol short term effects - intoxication
Slower reflexes Incoordination Sedation Memory problems Dilated blood vessels More urination
Alcohol physiological action
Agonist of GABA-A receptors and antagonists of NMDA receptors.
Alcohol long term effects
Cirrhosis of the liver which leads to liver failure
Brain damage (especially in the hippocampus with Korsakoff’s syndrome)
Foetal alcohol syndrome
Physical dependence to alcohol
Tolerance builds up from first night drinking.
Withdrawal takes place in hangover
After chronic use there can be very strong withdrawal symptoms (Delirium Tremens) which can be fatal
Psychological dependence on alcohol
Increases dopamine release in the n Accumbens (as do other NMDA receptor antagonists)
Strong heritable component to alcoholism
