Wk 26 - Opioid dependence in practice Flashcards
What is an opioid?
Natural derivative of opium w/ agonist + antagonist activity at opioid receptors
Which opiate has the greatest potential for dependence?
Diamorphine
When can physical + psychological dependce develop?
2-10 days of continuous use
What are the complications of opioid dependence?
- OD
- HIV + hep
- Homelessness + crime
What are the key elements of opioid dependence?
- Strong compulsion to take opioid
- Physiological w/drawal
- Tolerance
- Neglect of pleasures + interest
- Persistent use despite harmful consequences
What is opioid dependence managed by?
- Opioid sub therapy
- Psychological support
What is the aim of OST?
- Improve qual of life
- Red harm of using drugs
What is the dose for methadone?
- Initiation: 10-30mg/day
- <20 if: tolerance uncertain/taking other sedatives
- Maintenance: 60-120mg
- Inc risk QT prolongation: >100mg
What are the interactions of methadone?
- Affected by CYP450 inducers + inhibitors
- Respiratory depression by other CNS depressants
- QT prolongation
What are the adverse effects of methadone?
- Clouded mind
- Opiate s/e
- QT prolongation
- Torsades de pointes
What needs to be monitored when using methadone?
- BP
- Pulse
- LFTs
- U+E
- ECG
What are the signs of QT prolongation?
- Palpitation
- Syncope
- Dizziness
- Lightheadedness
- > 500ms
What is the dose for buprenorphine?
- Max 32mg
- Typical: 12-16mg
What are the adverse effects of buprenorphine?
- Less sedating than methadone
- Hepatic necrosis
What are the cautions + contraindications of buprenorphine?
- Liver dysfunction
- Hep B + C
- Hepatotoxic drugs
Give examples of reasons to suspect opioid dependency
- Drug misuse: OD, HIV, poor dental care
- Intoxication: itching, lower BP, constriction of pupils
- W/drawal: watering eyes, sneezing, clammy skin, tremor, HT
- Physical: tracks, poor nutrition
What does a drug assessment often include?
- History taking
- Urine drug screen
- ECG
- LFT
- U+E
- FBC
- Hep B + C + HIV
Urine drug samples
- Prior to OST + every 3 months
- Heroin: 48hr
- Methadone: 7-9 days
- Buprenorphine: 1-2 wks
What is maintenance OST?
- Indication: red use but not ready to come off completely
- Supervision consumption arranged for 1st 3 months
What is detoxification?
- Indication: Drug free
- Takes 28 days inpatient + 12 wks community
- Initiated once stabilised on OST
Outline the detoxification programme
Methadone:
- Red rate where 12 wks = 0
- Red 5mg every 1-2 wks
Buprenorphine:
- Red initially by 2mg every 2 wks
- Final red 400mcg
Give examples of symptomatic treatment to manage withdrawal
- Di - Loperamide
- Nausea + vom - Metoclopramide
- Stomach pain - mebeverine
- Aches/pains - paracetamol/ibuprofen
- Agitation/anxiety - diazepam/zopiclone
What is given during detoxification programmes to prevent relapse?
Naltrexone
How is methadone maintenance initiated?
- Initial: 10-30mg/day
- Heavily dependent: 40mg
- No more than 5-10mg inc in 1 day
- No more than 30mg inc in 1 wk
- 3-10 days to reach steady state
What are the risk factors for overdose on induction?
- Low opioid tolerance
- CNS depressant drugs
- Interactions
- Too high initial
- Rapid dose inc
What happens in subsequent optimisation in methadone maintenance?
- Titrate against w/drawal symptoms
- Inc 60-120mg/day
- Inc w/ 3-5 days btw dose change
How is buprenorphine initiated (day 1)?
- Start 4mg (mild-mod) to 8mg (mod-severe)
- 4mg if unknown dependency or polydrug use
- Wait 6-12 hrs after last heroin use or 24-28hr after last low-dose methadone
What happens in day 2 of giving buprenorphine?
- Rapidly titrate dose
- 2mg, 4mg or 8mg
- Aim: stable effects for 24hrs
- Maintenance: 12mg to 24mg
- Max 32mg
Which opioid is safer to initiate?
Buprenorphine - less over sedation, respiratory depression + OD
What are signs of overdose?
- Pinpoint pupils (miosis)
- Respiratory depression
- Unresponsive
- Sedation
What is the management for opioid toxicity?
Naloxone
Buprenorphine over methadone
- Safer in OD
- Patient dependent on codeine + hydrocodeine
- Cease heroin use
- Less affected by inducers + inhibitors
- Clear head
- Less sedating
Methadone over buprenorphine
- Easier to supervise
- For high levels of heroin
- Sedation is required
- Other opioids prescribed
What is suboxone?
Sublingual tab of naloxone w/ buprenorphine
What is a missed dose + what happens when it occurs?
- Missed 3 days (lost tolerance)
- Restart initiation
