Addictions Flashcards
What areas of the brain are associated with reward systems?
- ventral tegmental area
- nucleus accumbent
- prefrontal cortex
What are 2 examples of stimulant-type drugs?
- cocaine
- amphetamine
How is cocaine taken?
- coca leaves chewed or brewed
- cocaine hydrochloride is snorted or injected
- crack cocaine is smoked
What are the desired effects of taking cocaine?
- temporary stimulant and euphoriant (short lived)
- increases alertness and energy
- increased confidence and impaired judgement
- lessens appetite and desire for sleep
What are the bad effects of taking cocaine?
- damage to nose and airways
- convulsions with respiratory failure
- cardiac arrhythmias and MI
- hypertension and CVA
- toxic confusion
- paranoid psychosis
What are withdrawal effects of taking cocaine?
-depression
-irritability
-agitation
-craving
-hyperphagia
-hypersomnia
(reverse of desired effects)
How is amphetamine taken?
- sniffed
- swallowed
- injected
What are the desired effects of taking amphetamine?
similar to cocaine but effects are longer lasting
What are adverse effects of taking amphetamine?
- toxic confusion occasionally with convulsions and death
- amphetamine psychosis in heavy chronic use
What are examples of opiates?
- opium
- morphine
- heroin
- methadone
- codeine and dihydrocodeine
What are the 2 different substance types of heroin?
- tar like substance
- powder
How is heroin taken?
- snorting
- injecting
- smoking
What are the effects of opiates?
- analgesia
- drowsiness and sleep
- mood change (euphoria, intense pleasure)
- respiratory depression
- cough reflex depression
- sensitisation of the labyrinth with nausea and vomiting
- decreased sympathetic outflow (bradycardia and hypotension)
- lowering of body temperature
- pupillary constriction
- constipation
What signs are almost pathognomic of opiate overdose in adults? What are other signs?
- respiratory arrest with a pulse!!!!
- pinpoint pupils unreactive to light
- snoring giving way to shallow respiration
- bradycardia and hypotension
- varying degree of reduced consciousness/coma
What is the desired effect for people who abuse opiates?
- feelings of pleasure
- physical and emotional anaesthetic
What are side effects of taking opiates for the first time?
- nausea/vomiting
- headache
What are side effects of taking opiates medium term?
- phlebitis
- anorexia
- constipation
What are side effects of taking opiates longer term?
- tolerance
- withdrawal
- social and health problems
What are signs/symptoms of opiate withdrawal?
- craving
- insomnia
- yawning
- muscle pain and cramps
- increased salivary, nasal and lacrimal secretions
- dilated pupils
- piloerection (cold turkey)
Why is methadone prescribed?
to try and prevent the harmful effects of taking heroin e.g. infection risk, overdose risk etc
How is ecstasy (MDMA) taken?
orally
What is the desired effect of ecstasy?
- relaxed euphoric state without hallucinations
- euphoria followed by a feeling of calm
- increased sociability
- effects after 20 mins lasting 2-4 hours
What is particularly dangerous about taking ecstasy?
half of all ecstasy tablets contain no MDMA - instead they may have LSD, amphetamine, ketamine etc
What are side effects of taking ecstasy?
- nausea and dry mouth
- increased blood pressure and temperature
- in clubs users risk dehydration
- large doses can cause anxiety and panic
- drug induced psychosis
How is cannabis taken?
- smoked
- eaten
What are the psychological effects of taking cannabis?
- relaxing or stimulating
- euphoriant
- increases sociability and hilarity
- increases appetite
- changes in time perception
- synaesthesia e.g hear colours
in higher doses:
- anxiety
- panic
- persecutory ideation
- hallucinatory activity
What are adverse effects of taking cannabis?
- respiratory problems as with tobacco
- toxic confusion
- exacerbation of major mental illness
- cannabis psychosis?
What are anabolic steroids?
family of drugs comprising testosterone and many synthetic analogues
Why would people want to use anabolic steroids?
to enhance appearance or increase muscle mass and reduce body fat
In what areas of the body is muscle hypertrophy from steroid use particularly marked?
upper body in the pectoralis, trapezius and biceps
What are side effects of using anabolic steroids?
- acne, stretch marks, baldness
- feminisation in males with hypogonadism and gynaecomastia
- virilisation in women including hirsutism, deep voice, clitoral enlargement, menstrual irregularities, hair thinning
- increased cholesterol and hypertension
- growth deficits due to premature closure of epiphyses
- liver disease - cholestatic jaundice, liver tumours
What are psychological side effects of taking anabolic steroids?
- irritability
- hypomania and mania
- depression and suicidality on withdrawal
What is ‘tolerance’?
reduced responsiveness to a drug due to previous administration
What are the 2 main physiological mechanisms that may explain tolerance?
- dispositional (what macro body does with drug)
- pharmacodynamic (what happens at receptors)
What is the ‘dispositional’ theory as to why tolerance happens?
the more times the drug is administered, the less drug that reach the active site because of:
- decreased rate of absorption
- increased rate of metabolism to inactive metabolites
- decreased rate of metabolism to active metabolites
- increased rate of excretion
What is the ‘pharmacodynamic’ theory as to why tolerance happens?
the more times the drug is administered, the more the site of action becomes less affected by the drug because of:
- down-regulation or internalisation of drug receptors
- reduced signalling down stream of drug receptors
- some other compensatory mechanism
Why would we say that tolerance almost equates to dependence?
- our body wants to maintain homeostasis and administering a drug upsets that
- the body tries to adapt to the new body stage with the drug (creates compensatory mechanisms to ensure equilibrium)
- if stop taking it, then this upsets homeostasis and the body complains. Hence, withdrawal effects (these are usually the reverse of the effects of taking the drug e.g. opiate use leading to constipation, withdrawal effect is diarrhoea)
What neurotransmitter is involved in the reward centres?
dopamine
What normally activates the reward centres?
eating, drinking and sex
How does the reward centres theory relate to drug addiction?
some drugs can ‘tap in’ to reward pathway to increase dopamine levels and therefore increase desirability of drug ‘craving’
