Substance Misuse Flashcards
what is the modern phenomenom about substance misuse?
it is the global scale at which it occurs and the many different types of compounds taken
what does substance misuse mean ?
substances used outside of the therapeutic or clinical sense
what drugs are in class A?
ecstasy, heroin, cocaine and LSD
what drugs are in class B ?
amphetamines and cannabis
what drugs are in class C?
GHB and ketamine
what are the factors of Nutt harm to users about substance misuse?
drug specific mortality= death due to acute overdose
drug related mortality= death from illness caused by taking drug
drug specific physical harm= toxic effects short of death
drug related physical harm= injuries related to drug use short of death
dependence= addiction
drug specific impairment of mental function= impaired judgement causing risky behaviours
drug related impairment of mental function= psychological effects
loss of tangibles= impact on income
loss of relationships
crime
economic
impact on family life
injury
damage to communities
international damage
environmental damage
from Nutt what substance causes the greatest overall harm ?
alcohol
what is crude opium and where does it come from ?
dried juice (latex) from green capsule of poppy papaver somniferum
how much does each green capsule produce of opium ?
10-100mg of opium
how long has opium been around ?
since about 4000BC - poppy plant was referred to as the plant of joy
first century AD greek physician dioscorides summarised what was known about opium in his work de materia medica
when was the use of opium in europe well established ?
by 16th century
what is present in the latex?
lots of alkaloids- including morphine (<2.5%)
morphine was first isolated by serturner in 1807
what did greco-roman physicans realise about opium ?
aware that it was addictive and potentially dangerous
too much produced a deep sleep from which patient didnt recover
when did opiums presence decrease?
once morphine was introduced and later in 19th century when heroin was introduced
also at the beginning of the 20th century open sale and self med of additive drugs was no longer acceptable
what was developed in 1874 from morphine ?
C.R Alder Wright produced diacetylmorphone by acetylation of morphine
what happened to diacetylmethylation in 1897?
bayer, hoffman and eichengrun made it and marketed as heroin for treatment of pain and tubercular coughs
who first banned opium ?
usa in
prohibited import apart from for medical uses
in 1920a heroin was banned
what are the 3 classes of opioid receptors ?
Mu, Kappa and delta
stimulated by endogenous opioid peptides including endorphins, enkephalins and dynorphin and also by opioid agonists
what are examples of opioid antagonists ?
naloxone - has to be given intravenously
naltrexone- taken orally
what happens when Mu is activated ?
analgesia euphoria respiratory depression inhibition of gastrointestinal smooth muscle miosis
what is the users experience of opiates dependent upon ?
pharmacology of the drug and the set and setting of drug use
what happens when kappa receptor is activated ?
analgesia
sedation
hallucinations
possibly hypothermia
what happens when delta receptors are activated ?
analgesia
respiratory depression
inhibition of gastrointestinal activity
what is the most important acute toxic effect of morphine and heroin ?
respiratory depression - depression of the activity within the brain
why is tolerance so important with the administration of opiates ?
because many cases of fatal overdose involve the loss of tolerance
- some people can tolerate 100x the dose which would kill someone else
- if this tolerance is lost for example in rehab or prison
- if relapse occurs this is dangerous because the person will fall back into former pattern of drug consumption but they wont be able to tolerate it so it can be fatal
what is quite remarkable about opiates ?
relatively non-toxic= dont damage liver, CNS or cardiovascular system
what are the risks associated with intravenous use ?
HIV
hepatitis B and C
bacterial infection
what are the early stages of drug use characterised by ?
nausea itching then followed by warm feeling in abdomen sedation drowsiness
physical pain and stresses like anxiety are replaced by competence, optimism, power and detachment
what can heroin use in pregnancy cause ?
low birth weight
heroin dependent neonates
what drugs can be used to treat addiction of heroin ?
oral methadone used to be used but now buprenorphone is used as it is safer in overdose and withdrawal
when were amphetamines first synthesised ?
synthesised in late 1880s but not used clinically until early 1930s
what was it used for clinically in 1930s ?
active constituent in benzedrine inhaler to treat asthma, common cold and hay fever
nasal decongestant
what did it soon get used for ?
as a psychostimulant and anorexic effect (suppresses appetite)
why was amphetamine and methamphetamine used during WW2 ?
to combat fatigue and improve physical and mental endurance
after the war where were ampethamines used ?
abused as ‘pep pills’ in work environments with high levels of vigilance - pilots and lorry drivers
what ampethamines are used for treatment of narcolepsy ?
modafinil and dexamphetamine
what amphetamines are used to treat ADHD?
MPH/ritalin
what amphetamines were used as anti-obesity agents ?
dexamphetamine
fen-phen combination= fenfluramine and phentermine - use has declined as it causes thickening of pulmonary artery causing pulmonary hypertension
what are the acute adverse effects of amphetamines ?
sympathomimetic toxidrome
cardiovascular toxicity= high bp, haemorrhagic stroke, cardiovascular collapse secondary to ventricular fibrillation
hyperthermia
amphetamine psychosis= auditory, visual and tactile hallucinations, paranoia, anxiety and fear
what are the long term adverse effects of amphetamines ?
addiction
neurotoxicity- cognitive impairment (?)
self injurious and violent behaviours
what are amphetamines referred to as and what effects are produced ?
psychostimulants
- euphoria
- enhanced alertness
- hyperactivity
- increased confidence
- talkativeness
- anorexia
- in fatigue they improve physical and mental performance - only simple tasks
what is ecstasy ?
first synthesised about 100 years ago
produced amphetamine like effcts
what are the effects of ecstasy ?
may have neuroprotective effects
hyperthermia
hyponatremia- excess water intake and increased ADH secretion leading to enhance water reabsorption
hepatotoxicity
serotonin syndrome- interactions with SSRIs
what are the psychostimulant effects of amphetamines thought to cause ?
increased release of monoamine neurotransmitters - dopamine, noradrenaline and serotonin
substrates for monoamine transporters to mediate entry into presynpatic terminal
increase release from storage vesicles
what behaviours are often associated with amphetamine use ?
self mutilation and violent behaviours
what happens with withdrawal from amphetamines ?
depression
unhappiness and intense craving of the drug
