Management of Opiate Misuse

Question 1

most common drug used in month prior to assessment in illicit drug users?

Answer 1

heroin

Question 2

what 3 features of heroin contribute to the addictiveness of heroin?

Answer 2

rapidity of onset of action

short half life

Question 3

where does heroin come from?

Answer 3

opium poppy

Question 4

what is problem drug use?

Answer 4

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

Question 5

opium is used to form morphine

morphine then used to form diamorphine, describe each form

Answer 5

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)

Question 6

how can you take heroin (in order of popularity)?

Answer 6

IV
smoking
suppository
insufflation
ingestion

Question 7

basic early metabolic pathway of heroin?

Answer 7

diacetylmorphine > 6-monoacetyl morphine > morphine

Question 8

8 effects of heroin?

Answer 8

euphoria
analgesia
resp depression
constipation
reduced consciousness
hypotension and bradycardia
pupillary constriction
tolerance with repeated use

Question 9

what are the symptoms of heroin withdrawal?

Answer 9

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

Question 10

main complications of IV drug use?

Answer 10

infection
- local = cellulitis, abscess, thrombophlebitis, necrotising fascitis 
- distant = infective endocarditis
- systemic = Hep B, HIV, Hep C
thrombosis/embolism
- DVT, PTE, ischaemic limb

Question 11

mean age of people dying of drug related death?

Answer 11

41

Question 12

does heroin cause psychosis?

Answer 12

no

opiates are the only sedative drug that are marked by an antipsychotic effect

Question 13

options for clinical treatment of opiate addiction?

Answer 13

opiate substitution therapy (OST)
opiate detoxification
psychosocial interventions (CBT, couples therapy, contingency management)

Question 14

goals of treatment in opiod dependence?

Answer 14

reduce harm
promote recovery
maintain abstinence

Question 15

what is OST?

Answer 15

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

Question 16

pros and cons of OST?

Answer 16

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

Question 17

what can be prescribed?

Answer 17

opiod replacement therapy (methadone, buprenorphine)
opiod detox (methadone, buprenorphine, lofexidine)
opioid antagonist (naltrexone, naloxone)

Question 18

action of methadone and buprenorphine?

Answer 18

methadone = long acting full agonist
buprenorphine = long acting partial agonist

Question 19

ideal substitution medication should be what?

Answer 19

safe and well tolerated
stop withdrawal
not addictive
have a long effect

Question 20

what is opiate detoxification?

Answer 20

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

Question 21

methadone prescription?

Answer 21

liquid preparation 1mg/1ml

Question 22

buprenorphine prescritpion?

Answer 22

in lots of different preparations

- generic, subtex, espranor, suboxone

Question 23

which is more potent, methadone or buprenorphine?

Answer 23

methadone (methadone is a full rather than a partial opiate agonist)
methadone therefore has a larger opioid effect

Question 24

methadone vs buprenorphine overdose?

Answer 24

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

Question 25

pros of buprenorphine vs methadone?

Answer 25

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

Question 26

cons of buprenorphine vs methadone?

Answer 26

not indicated for patient susing high doses of opioids
can be misused (injected/snorted)
risk of induced withdrawal
less sedative (clear head)

Question 27

induction and maintenence of methadone?

Answer 27

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

Question 28

induction and maintenence of buprenorphine?

Answer 28

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

Question 29

appropriate dose of substitution?

Answer 29

where patient stops using and is not having cravings

can be much higher than dose needed to stop withdrawal

Question 30

3 days rule?

Answer 30

if medication is not collected for 3 days, the pharmacist must get advice from the prescriber on what action to take

Question 31

what is a steady state in methadone dosing?

Answer 31

the dose at which in the time between each dose, the rise and fall of drug concentration is the same between each dose