OPIOD Analgesics

Question 1

What is the indication for opiod analgesics

Answer 1

treatment of acute and chronic pain

Question 2

What is the mechanism of action of opioid analgesics

Answer 2

They act of mu receptors in the brain and the git tract to disrupt pain singnals sent to the brain

Question 3

What are the precautions when taking opiods

Answer 3

• 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

Question 4

What are the main adverse effects of opioids

Answer 4

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

Question 5

When do you tapper down dose of opioids

Answer 5

• 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

Question 6

What re the councelling points and practice points for OPiods

Answer 6

• 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
• -

Question 7

1. Buprenorphine- class, moa, indication

Answer 7

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

Question 8

Buprenorphine- dose , counselling, Monitoring

Answer 8

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

Question 9

Codeine - what is the indication, moa, class

Answer 9

class- weak opiod, converts into active prodrug morphine in body via cyp2d6

Question 10

Why is codeine not a suitable pain analgesic

Answer 10

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

Question 11

why was codeine schedule moved to s3

Answer 11

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

Question 12

Codeine what is the dose , counselling points

Answer 12

30-60mg(1-2 )every 4-6 hour- maximum of 240mg daily

Question 13

Codeine - what are the contraindications

Answer 13

Not to be used in children 12 years or under
Those aged <18years undergoing tonsillectomy/ adenoidectomy
- avoid use in sleep apnoea

Question 14

Fentanyl- what is the MOa, class, indication

Answer 14

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

Question 15

What are the recent changes made for Fentanyl and who is it suitable for

Answer 15

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.

Question 16

Fentanyl - what is the dosing regimes for preparations avaliable

Answer 16

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

Question 17

Counselling / practice points for fentanyl

Answer 17

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

Question 18

What are the Precautions /contraindications for fentanyl-

Answer 18

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

Question 19

Hydromorphone - what is the moa, indication, class

Answer 19

Class-opiod agonist
MOA- same
Indication - sever pain under speicalist

Question 20

HYdromorphone- what is the dose, class, indication

Answer 20

oral tablegt- 0.5-2mg every 4 hours

Question 21

what is the dose for Hydromorphone, counselling points and practice points

Answer 21

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

Question 22

Methadone- what is the Indication, class, MOA,

Answer 22

class- opioid agonist
indication- sever pain or drug dependence management

Question 23

Methadone - what is the dose

Answer 23

dose depends on pain specialist

Question 24

What are the precautions with methadone

Answer 24

can prolong QT interval- increasing risk for causing arrhythmia- monitor in pt with arrythmia, heart effects

Question 25

Oxycodone- class, indication, MOA

Answer 25

Class -Opiod agonist
Indication
–sever pain ( hronic cancer pain)
–For patients intolerant to morphine

Question 26

oxycodone - what are the precautions of oxycodone

Answer 26

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

Question 27

what is the dose ,councelling/practice points

Answer 27

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

Question 28

What other forms does oxycodone come in

Answer 28

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

Question 29

Tramadol -indications , dose , class

Answer 29

partial mu agonist-
for moderate to sever pain
moa- partial antagonises mu recepots but also inhibits reuptake of nor nr and seratonin

Question 30

tramadol dose , counselling points, practice points

Answer 30

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

Question 31

What are the precautions for tramadol

Answer 31

seratoin toxicity- if taken with 14 days of MAOI or other drugs that work on seratonin and nr reuptake inhibition

Question 32

Tapentadol-class, indication, MOA

Answer 32

Class -opioid agonist
Indication- sever pain
binds to mu receptors but also noradrenalin reuptake inhibitors

Question 33

What is the dose of Tapentadol,

Answer 33

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

Question 34

Tapentadol counselling
points, practice points

Answer 34

analgesic starts with in 30-45mins of dose
Contraindicated within 14 days of MAOI