Management of Opiate Misuse Flashcards
most common drug used in month prior to assessment in illicit drug users?
heroin
what 3 features of heroin contribute to the addictiveness of heroin?
rapidity of onset of action
short half life
where does heroin come from?
opium poppy
what is problem drug use?
problematic use of opiates (including illicit and prescribed methadone use) and/or the illicit use of benzodiazepines and implies routine and prolonged use as opposed to recreational and occasional use
opium is used to form morphine
morphine then used to form diamorphine, describe each form
opium = mixture of alkaloids (esp codein and morphine) morphine = morphine extracted though often codeine contaminents remain) diamorphine = addition of 2 acetyl rings to produce diacetylmorphine (diamorphine)
how can you take heroin (in order of popularity)?
IV smoking suppository insufflation ingestion
basic early metabolic pathway of heroin?
diacetylmorphine > 6-monoacetyl morphine > morphine
8 effects of heroin?
euphoria analgesia resp depression constipation reduced consciousness hypotension and bradycardia pupillary constriction tolerance with repeated use
what are the symptoms of heroin withdrawal?
typically within 6-8 hours dysphoria and cravings agitation tachycardia and hypertension piloerection diarrhoea, nausea and vomiting dilated pupils joint pains yawning runny nose and watery eyes
main complications of IV drug use?
infection - local = cellulitis, abscess, thrombophlebitis, necrotising fascitis - distant = infective endocarditis - systemic = Hep B, HIV, Hep C thrombosis/embolism - DVT, PTE, ischaemic limb
mean age of people dying of drug related death?
41
does heroin cause psychosis?
no
opiates are the only sedative drug that are marked by an antipsychotic effect
options for clinical treatment of opiate addiction?
opiate substitution therapy (OST)
opiate detoxification
psychosocial interventions (CBT, couples therapy, contingency management)
goals of treatment in opiod dependence?
reduce harm
promote recovery
maintain abstinence
what is OST?
used mainly for opioid dependence but can be used in benzodiazepine, alcohol or stimulant dependence
replacement of a short acting opiate with a long acting opiate (methadone or buprenorphine)
taken once daily under supervision
pros and cons of OST?
pros - reduce mortality rate - reduced HIV risk - may prevent Hep C - can reduced odds of new Hep C when combined with NSP - reduced criminality - improves social/family life and employment cons - daily visits to chemist - stigma - side effects - cost
what can be prescribed?
opiod replacement therapy (methadone, buprenorphine) opiod detox (methadone, buprenorphine, lofexidine) opioid antagonist (naltrexone, naloxone)
action of methadone and buprenorphine?
methadone = long acting full agonist buprenorphine = long acting partial agonist
ideal substitution medication should be what?
safe and well tolerated
stop withdrawal
not addictive
have a long effect
what is opiate detoxification?
complete abstinence from all opiates
can be from variety of methods (methadone etc)
if abstinence is achieved and maintained then potential to realise a lot of social, physical and psychiatric benefits
methadone prescription?
liquid preparation 1mg/1ml
buprenorphine prescritpion?
in lots of different preparations
- generic, subtex, espranor, suboxone
which is more potent, methadone or buprenorphine?
methadone (methadone is a full rather than a partial opiate agonist)
methadone therefore has a larger opioid effect
methadone vs buprenorphine overdose?
no real max dose of buprennorphine (opiod effect plateaus at a certain level and will not give any more effect with larger dose)
max dose exists for methadone as opioid effect increases with increasing dose
pros of buprenorphine vs methadone?
safer
less sedative (clear head)
more likely to block the effect of using on top
longer effect (taken every other day)
quicker titration (2-3 days instead of weeks/months)
easier to detox from
less stigma
cons of buprenorphine vs methadone?
not indicated for patient susing high doses of opioids
can be misused (injected/snorted)
risk of induced withdrawal
less sedative (clear head)
induction and maintenence of methadone?
starting dose = 10-30mg
week 1 = increase by max 10mg/day, max 30mg/week
5 days to the steady state (meaning??0
usual effective dose = 60-120mg
no max dose
higher risk of overdose in first few weeks
induction and maintenence of buprenorphine?
starting dose = 4-8mg second day = up to 16mg usual effective dose = 12-16mg max dose = 32mg per day take single dose in the morning
appropriate dose of substitution?
where patient stops using and is not having cravings
can be much higher than dose needed to stop withdrawal
3 days rule?
if medication is not collected for 3 days, the pharmacist must get advice from the prescriber on what action to take
what is a steady state in methadone dosing?
the dose at which in the time between each dose, the rise and fall of drug concentration is the same between each dose
