What complications are involved?
Overdose, HIV, hepatitis, homelessness & crime
What is opioid dependence?
Dependence which develops after regular use of opioids
What is the key element of opioid dependence?
A strong desire/sense to take opioids
What is OST?
Opioid substitution therapy
- Pharmacological: buprenorphine/methadone
- Psychosocial support
What is the aim of OST?
- Improve QOL of opioid-dependent patients
- Reduce illicit opioid use
- Prevent people dropping out of treatment
- Reduce crime
- Reduce risk of BBV transmission
- Reduce mortality
Is methadone a partial or full agonist and what dose should it be initiated at?
Full
10-30mg/day
When is there an increased risk of QT prolongation with methadone?
Dose >100mg
Is buprenorphine partial or full?
Partial opioid agonist at mu receptors and antagonist at k receptors
Differences between opioid intoxication and acute withdrawal syndrome?
Intoxication: lower BP, hypoventilation, constriction of pupils, slower pulse
AWS: dilated pupils, cough, clammy skin, yawning, sneezing, watering eyes, increased pulse, raised BP, runny nose, nausea, diarrhoea
Features of suspected opioid dependency
- Psychiatric: overdose, depression
- Forensic: probation, community service
- Social: family problems, unemployment, financial
Physical exam features
- Poor nutrition
- Dental hygiene
- Needle tracks
- Skin abcess
Drug and alcohol assessment
Degree of dependence
Medical history
Psychiatric history
Social history
Family history
Urine/drug screen
ECG, U+Es, FBC, LFT, Screen for HIV/Hep B&C
How often to test urine and how long do substances show?
3 months
Heroin: up to 48 hours
Methadone: 7-9 days
Buprenorphine: 1-2 weeks
Shorter detection window for mouth swab but can be done
Difference between maintenance and detoxification
Maintenance is for patients who wish to reduce but are not ready to completely stop the use of opioids
- Reduce illicit drug use, reduce harm & stabilise life
- Supervised for 3 months
Detoxification for patients who wish to become drug-free
- 28 days as an inpatient and 12 weeks in community
- Minimise withdrawal symptoms
Why is the ultra-rapid detox not recommended?
High rate of relapse
What are the symptomatic treatment to manage withdrawal for each?
- Diarrhoea
- Nausea/vomiting
- Stomach pain/cramping
- Aches/pains
- Agitation/anxiety
- Loperamide
- Metoclopramide
- Mebeverine
- Paracetamol/ibuprofen
- Zopiclone/diazepam
What is used for relapse prevention?
Naltrexone
Which treatment is first line and how is it chosen?
- Methadone first line but both equally as effective
Based on
- preference for either drug
- previous benefit
- safety concerns
- drug-drug interactions
- pregnancy (complex as withdrawing the baby)
- severity of dependence
How to initiate methadone?
- Start low, go slow (long acting synthetic opioid)
What are the risk factors for overdose
- Low opioid tolerance
- Use of CNS depressant drugs
- Drug interactions
- Rapid dose increase
- Slow methadone clearance (hepatic impairment)
What is the increase to methadone usually?
60-120mg/day
How to initiate buprenorphine
- Ideally wait 6-12hrs after last use of heroin
- 24-48hrs after last dose of methadone
Safer to initiate than methadone
Less risk of over-sedation, respiratory depression & overdose
What to do when initiating methadone/buprenorphine
Start low dose & titrate rapidly
How many missed doses?
3 days
