OPIOD Analgesics Flashcards
What is the indication for opiod analgesics
treatment of acute and chronic pain
What is the mechanism of action of opioid analgesics
They act of mu receptors in the brain and the git tract to disrupt pain singnals sent to the brain
What are the precautions when taking opiods
- Taking other Cns and Respiratory depressants- ie benzodiazapines, pregablin and gapapentin- can exacerbate effects- AVOID combination if possible
Respiratory depression- use in caution in patients who have sever respiratory depression, asthma, sever obstructive airway disease( COPD, pneumonia)
Renal- avoid codeine due to toxic metabolite accumulating - Choice of opiods in renal imp- tapentadol/ oxycodone -
Use tramadol, morpinw with caution
Elderly- reduce dose - increase risk of sedation,resp depression and falls( 25%-50% of adult dose )
Pregnancy-Avoid use can cause resp depression in neonate
Breast feeding_ Avoid codeine, Can take other opioid’s but caution with repeated doses and monitor infant for sedation
What are the main adverse effects of opioids
Common - nausea dizziness, drowsiness, orthostatic hypotension, dry mouth, urinary retention, constipation
–>Constipation- increase fluid and
fibre intake during use of opioid.
When used for chronic pain or
palliative care- give laxative at same
time of opioid use
-Physical dependence- need for patient to continue using opioid
- Main adverse effect- respiratory depression- monitor sedation via sedation score - aim of score<2(* easy to rouse, but cannot stay awake*)
With drawl effects- when antagonist is given or opioid dose is stopped suddenly
> anxiety, , nausea, vomiting, diarrhoea, sweating
When do you tapper down dose of opioids
- when opioid is being used after acute pain treatment
- if significant advisers effects occur
- If used for chronic non cancer pain> 90days
- if risk of misuse or overdose is noted
What re the councelling points and practice points for OPiods
- label 1 - may make you feel dizy and drowsy do not use machineary if impacted
- Effects can be increased if used with alcohol
- If very slepy and difficulty staying away( (sedation Increased) Increased risk for resp depression notify doc
- If opiods used regulary- can take laxatives for opiod induced constipation
- If used long term - monitor for dental carries can cause cavities due to dry mouth
- -
- Buprenorphine- class, moa, indication
class- partial opioid agonist
MOA- Partially activates the receptor, pot gets pain relief with out full pleasure effects/ getting high
Indication- chronic pain, addiction, patients with substance abuse as they are less likely to have withdrawal effects
Buprenorphine- dose , counselling, Monitoring
dose- sublingual- 200-400micg every 4-6 hours
Patch-( long acting) 5mig/hr -Titrating dose no less than 3 days- Max daily dose- 40mig/d
Sublingual tablets- place under tongue until dissolved - NO CRUSHING
Patch - change every 7 days changing sites every time -Apply to clean, intact, non-irritated, non-hairy, scar less skin of upper outer arm, chest, upper back, side of chest
Avoid applying patch to same site 3-4 weeks
Avoid heat as it increase release of buprenorphine ie sauna , electric blankets, hot baths
If other analgesic is needed- use non opiod analgeic ie paracetamol, nsaid before considering opiod
Codeine - what is the indication, moa, class
class- weak opiod, converts into active prodrug morphine in body via cyp2d6
Why is codeine not a suitable pain analgesic
Its efficacy is depended on the gene expression of cyp2d6 enzyme to convert it to morphine. Some ethnicity’s lack expression of enzyme hence effect of pain relief differs
why was codeine schedule moved to s3
taking codeine fore pain relief with paracetamol was no more beneficial than other non opiods for pain relief( nsaid, paracetamol).
- increased risk of misuse, dependence, resp depression
Codeine what is the dose , counselling points
30-60mg(1-2 )every 4-6 hour- maximum of 240mg daily
Codeine - what are the contraindications
Not to be used in children 12 years or under
Those aged <18years undergoing tonsillectomy/ adenoidectomy
- avoid use in sleep apnoea
Fentanyl- what is the MOa, class, indication
Class opioid agonist- 100 more potent than morphine
MOA- binds o mu receptors in brain- disrupts signals of pain to body
Indication- sever chronic pain( where other opioid have failed
- Opioid adjunct with general anaesthesia
- Breakthrough pain for non cancer pain patients already stabilised on opiod
What are the recent changes made for Fentanyl and who is it suitable for
Suitable for - Palliative care patient, cancer patients
- Last resort for patient who have already used other opioids and failed
- should not be used in opioid naïve pt.
Fentanyl - what is the dosing regimes for preparations avaliable
Comes in lozenges, patch, sublegal tablets
BRANDS are NOT INTERCHANGEABLE
> when switching brands begin with its starting dose and then titrate up- to minimise toxicity
Fentanyl lozenges and sublingual tablets should only be used for breath through pain when pt has already been stabilised on opiod equivi to 60mg morphine for 7 days
Each Formulation has different dosing and titration periods - CHECk amh
Counselling / practice points for fentanyl
Patches - not to be used for acute post operative pain due to increased risk of resp depression, delayed onset of action and prolonged duration,
- Patch is effective for 72 hours
- Avoid children touching patches- can cause death
- Avoid being in places with heat due to increase release of drug
SWITCHING from tablet to pacth
Lozenges/Sublingual tablet- takes 15 minutes to work, peak concentration at 20-40minutes
- Brands are not interchangeable- only stick to one brand
- If you have dry mouth moisten mouth with water before using and don’t eat or drink whilst in mouth
- Allow 30minuts for absorption then rinse with water
What are the Precautions /contraindications for fentanyl-
Precaution
>Serotonin toxicity - if taken with 14 days of ceasing MAOI or other SSRI,NRI, 5Ht3, triptans
>Dry mouth and diabetes- lozenges contain 2g of sugar - try other formulation( tabs)
Contraindicated
> Patches are contraindicated acute post opp pain
>Acute sever respiratory depression or disease- patches are contraindicated
Hydromorphone - what is the moa, indication, class
Class-opiod agonist
MOA- same
Indication - sever pain under speicalist
HYdromorphone- what is the dose, class, indication
oral tablegt- 0.5-2mg every 4 hours
what is the dose for Hydromorphone, counselling points and practice points
Should only be used in breakthrough pain for patients already stabilised on opioid ( MAINLY cancer pt ) -
- Use 1/12 of total daily dose of conventional product
Don use in chronic non non cancer pain
Dont use if patient has morphine, oxycodone, codeine allergy - SAME CLASS
Methadone- what is the Indication, class, MOA,
class- opioid agonist
indication- sever pain or drug dependence management
Methadone - what is the dose
dose depends on pain specialist
What are the precautions with methadone
can prolong QT interval- increasing risk for causing arrhythmia- monitor in pt with arrythmia, heart effects
Oxycodone- class, indication, MOA
Class -Opiod agonist
Indication
–sever pain ( hronic cancer pain)
–For patients intolerant to morphine
oxycodone - what are the precautions of oxycodone
Patients who have swallowing disorders-oesophageal narrowing, pt with sensory disorders autism
Oxycontin - can swell and become highly viscous in water causing choking, gagging
swallow with glass of water
what is the dose ,councelling/practice points
Oral tablet- 5-15mg every 4 hours
- Maintenance dosing -when stabilised give up to half daily dosing every 12 hours
Chronic cancer pain- 2.5-5mg every 4 hours
Chronic non cancer pain - not recommended but an give to a patient on a trail basis for 4-8 weeks
- start 5-10mg CR twice a day and review dose every 1-2 weeks
- if no improvement and on 30mg> after 4-8 weeks titrate down and cease
What other forms does oxycodone come in
Oxycodone/ naloxone- 5/2.5 or 10/5mg 12 hrly
Indicated
- Opioid induced constipation where laxatives have not worked
- Restless legs syndrome where dopamine agonist have not worked - naloxone reduces opioid induced GI adverse effects
Tramadol -indications , dose , class
partial mu agonist-
for moderate to sever pain
moa- partial antagonises mu recepots but also inhibits reuptake of nor nr and seratonin
tramadol dose , counselling points, practice points
conventional tab-50-100mg every 4-6 hours( maximum 300mg daily)
CR- 50- 100mg twice ailyt( maximum of 400mg)
Common A/e- cns stimulation can keep you up, sleep disturbnce
- rash- SJS syndrome
Cyp2d6
- Cucasian and asia- lack gene- may not have effective pain relief
African(ethiopian)/ middle eastern- fast metabolisers- increased toxicity
What are the precautions for tramadol
seratoin toxicity- if taken with 14 days of MAOI or other drugs that work on seratonin and nr reuptake inhibition
Tapentadol-class, indication, MOA
Class -opioid agonist
Indication- sever pain
binds to mu receptors but also noradrenalin reuptake inhibitors
What is the dose of Tapentadol,
IR 50-100mg (1-2 tablets) every 4-6 hours- Maximum of 600mg daily
CR- 50mg twice daily - increasing by 50 mg every 3 days if required
Maximum of 500mg daily
Tapentadol counselling
points, practice points
analgesic starts with in 30-45mins of dose
Contraindicated within 14 days of MAOI
