2 - addiciton lecutre — pathophysiology + clinical management Flashcards
definition of drug abuse
substance used in a manner that does not conform to social norms. can abuse drugs without being dependent or addicted
definition of drug dependence (physical)
individual depends on drug for normal physiological functioning. abstinence produced physical withdrawal reactions
definition of drug dependence (psychological)
acquiring and using drug are strong motivators of behaviour. compulsive use
definition of drug addiction
not a clinical diagnosis. typically used to emphasise psychological dependence. idea that people can be physically dependent but not addicted
diagnosing substance dependence pre 2013
3+ in last year:
- tolerance
- physical withdrawal state
- difficulties controlling use (amount, onset, stopping)
- strong desire/compulsion to take the substance
- progressive neglect of other interests
- persistence with substance despite detrimental effects — social, cognitive, physical
diagnosing substance use disorder from 2013
2-3: mild, 4-5: moderate, 6-7: severe
- tolerance
- withdrawal
- continuing to use despite the -ve personal consequences
- repeatedly unable to carry out major obligations
- recurrent use in physically hazardous situations
- continued use despite persistent or recurring social or interpersonal problems
- using greater amounts of using over a longer period of time than intended
- persistent desire or unsuccessful efforts to cut down
- spending a lot of time obtaining, using, or recovering
- stopping or reducing important social, occupational, or recreational activities
- consistent use despite persist or recurrent physical or psychological difficulties
- craving or a strong desire to use
when does drug tolerance occur?
when decreased sensitivity to a substance develops as a result of its continuous use
sites along where are really critical in the way the brain processes pleasure and reward?
medial forebrain bundle — extends from the ventral tegmental area in the brainstem, up towards the medial prefrontal cortex
what areas are there along the medial forebrain (sites of rewarding brain stimulation)?
all drugs of abuse increase dopamine levels in _____?
nucleus accumbens
what does cocaine block? effect?
the transporter that takes up excess dopamine — therefore increase in dopamine in synapse — increase in post-synaptic binding
what does GABA inhibit?
dopamine
what do opiates inhibit?
GABA — therefore more dopamine
describe drug tolerance
- chronic effect
- diminished response to drug — decreased effect or need more for same effect
- changes in endogenous dopamine release
- decreased receptors, receptor desensitisation and down-regulation
- need more drug to release same amount of dopamine and get same “high”
describe drug withdrawal
- “normal” function needs drug
- sudden cessation produces symptoms resulting from neurochemical cascade
- changes to release and receptors mean that functioning depends on exogenous dopamine
- without eternal stimulation, normal function compromised
describe cocaine in terms of acute use vs chronic use vs withdrawal
why do some people become dependent?
GXE interaction — dependence
> genetic/biological — familial, multi-gene eg. DA genes, brain changes
> environment — childhood, peer pressure, availability
what are the differences in clinical management of withdrawal in the acute term, medium term, and long term?
- acute : management of withdrawal
- medium : harm reduction, substitution
- long : maintaining abstinence
what % of people who go through short term detox treatments will relapse within a year?
75%
symptoms of 3 vs 10 vs 30 days of abstinence
what agonist can be used in opiate relapse prevention?
methadone
what partial agonist can be used in opiate relapse prevention?
buprenorphine
what antagonist can be used in opiate relapse prevention?
naltrexone
why are most deaths in opiate addicts accidental?
- accidental overdoses after detox
- detox removes tolerance
- people relapse to pre-detox dose — with no tolerance, it proves fatal
describe substitution pharmacotherapy in opiate addiciton
A : effects of opiates wanted by addicts — pleasure, reward
B : effects of opiates primarily not wanted — respiratory depression
IDEAL : give A, but not too much, without B
name 2 full agonists - opiates
- morphine
- methadone
how does naltrexone (opiate antagonist) work?
- blocks the mu opiate receptor
- leads to reduced DA-ergic activity
- reduced craving
- however…. bad adherance
what are 3 psychological treatments for addiction?
- motivational interviewing — non-confrontational, targets ambivalence
- community reinforcement — ‘earn’ tokens/money with clean urines
- relapse prevention — cognitive behavioural strategies, skills training (practise saying no), alternative cognitions (what else could i do?), lifestyle changes (relaxation training)
what is decriminalisation of drugs?
— NOT the same as legalisation
- for drug use and possession, criminal charges are not applied
- decriminalisation may replace criminal penalties with civil penalties eg. referral to an education or treatment program
- production, distribution and supply are still criminal offences
what are the advantages/disadvantages of drug decriminalisation?
+ves:
- civil cases do not lead to criminal records and will not affect employment, housing or travel opportunities
- treating drug use as a health and social issue rather than a crime can reduce stigma and increase the likelihood that a person will seek help
-ves:
- would drug use increase?????
what is drug legalisation?
- drug possession and use are legal
- regulations control production, distribution and supply
- no penalties if regulations are complied with
- may be criminal penalties if regulations aren’t followed
what are some reasons for and against cannabis legalisation?
