13- Symptom management (Pain and Opioid Prescribing) Flashcards
general principles for symptom management
Evaluation
- Prob and pattern recognition, direct enquiry
What is the cause of the symptom?
- Treatments
- Cancer
- Co-morbidity
What is the underlying pathological mechanism?
Is it reversible?
What has been tried?
What is the impact of the symptoms on the patients quality of life?
Pain management background
- 75-95% with advanced cancer experiencing pain
- Pain in patients with cancer
o Persistent paincan have multiple aetiologies
o Impairs function and threatens independence - Aim to optimise pain and minimise side effects
- > 50% of inpatients have their pain adequately controlled
types of pain
- nociceptive
–> somatic
–> viscerral - neuropathic
- mixed
- incident
Nociceptive pain
Types
- Visceral
- Somatic
normal nervous system, identifiable lesion causing tissue damage
Somatic pain
- originates from skin/ muscles/bone
- Sharp, throbbing, well localised
Visceral pain
- Originates from hollow viscus or solid organ
- Diffuse ache, difficult to localise
Neuropathic pain
malfunctioning nervous system; nerve structure is damaged
- Burning, tingling, pins and needles
Mixed pain (40%)
- nociceptive and neuropathic
Incident pain
pain which occurs due to certain events such as movement, coughing and dressing change
WHO ladder
Stage 1 (Non-opioids)
- Paracetamol
- Ibuprofen
- Paracetamol + Ibuprofen
Step 2
- Non-Opioids +
- Weak opioid (dihydrocodeine, codeine phosphate, tramadol, co-codamol)
Stage 3
- Non- opioid +
- Opioid (Oxycodone, morphine, fentanyl, diamorphine)
Who principles of prescribing
- Give regularly – not just PRN
- Where possible use oral route
- Prescribe regular and PRN – allows to titrate
- Monitor benefit
types pain relief
non-opioid
opioid
adjuvants
Non-opioids
- Paracetamol
- NSAIDs
- COX-2s
Opioids (from weak to strong)
- Codeine
- Co-codamol
- Tramadol
- Morphine
- Diamorphine
- Fentanyl
- Oxycodone
Adjuvants
- drugs whose primary indication is not for pain- when pain is only partially responsive to opioid analgesia*
- Antidepressants: amitriptyline, duloxetine
- Anti-convulsant: gabapentin, pregabalin
- Benzodiazepines: diazepam, clonazepam
- Steroids: dexamethasone
- Bisphosphonates for bony pain
Successful pain control involves…
- Regular and PRN doses
- Titration of dose against effect with no rigid upper limit for strong opioids
- Appropriate time interval between doses
- Sufficient dose to prevent return of pain before next dose is due
- Willingness to give strong opioids early when other analgesics fail
- Early consideration of adjuvants
- Regular review and assessment
- Follow analgesic ladder
- Appropriate explanation/information for patient
NSAIDS and COX-2 use in cancer
Due to inflammatory component common in cancer pain
- COX-2 now preferred unless patient at risk of sudden CV event
NSAIDS vs COX-2 inhibitors
COX-2 inhibitors are a type of NSAID.
Unlike traditional NSAIDs, COX-2 inhibitors work in a different way to control inflammation and pain.
COX-2 inhibitors are as effective as other NSAIDs at reducing pain and inflammation. However, they cause fewer stomach and intestinal problems, such as bleeding and ulcers
NSAID or COX-2: If a patient has no CV or GI risk
NSAID: ibuprofen or naproxen
NSAID or COX-2: If patient has GI risk but no CV risk ->
COX-2 e.g. celecoxib
NSAID or COX-2: If patient has CV risk but less GI risk
NSAID e.g. naproxen or ibuprofen
principles of using NSAIDs of COX-2
- Prescribe PPI for all
- Care in HF exacerbated by ALL
Paracetamol
- Must be over 50kg for full dose
- 1g- QDS regularly
Drugs for neuropathic pain
Examples:
- Amitriptyline start 10-25mg nocte (confusion, hypotension, care re CVS disease)
- Gabapentin 300mg TDS over 3/7
- Pregabalin 75mg BD
Side effects of neurophathic painkillers
- Sedation
- Tremor
- Confusion
- Dizziness
- Be careful if renal impairment (renally excreted- test function before)
Beware of AKI e.g. due to sepsis
Weak opioids (step 2)
- Can argue that no pharmacological need for weak opioids in cancer pain
- Low dose morphine often provides quicker and better pain relief tan weak opioids
- Weak opioids no longer recommended in children (step 2 skipped)
- E.g.
o Codeine
o Dihydrocodeine
o Tramadol - Ceiling effect for analgesia – side effect > benefits
key side effects of weak opioids
Tramadol is less constipating than codeine/dihydrocodeine but causes more N&V and anorexia
Strong opioids (step 3)
- Essential drugs in cancer care
- Undesirable effects generally related to central and peripheral Mu receptors activation (CNS and GI tract)
- Examples
o Morphine
o Oxycodone
o Diamorhinw
o Fentanyl
o Buprenorphine - Because of wide number of different formulation and brands available, prescribing by brand is encouraged to reduce risk of error/ confusion
Side effects of strong opioids
A. Pruritus
B. Rash
C. Constipation
D. Dry mouth
E. Nausea and vomiting
F. Urinary retention
G. Hypogonadism
H. Respiratory depression
I. Drowsiness/sedation
J. Confusion
Potential anxieties when commencing morphine?
- Addiction
- Tolerance/loss of effectiveness
- The end of the road Last resort
- Severe side effects
causes of opioid toxicity
- Dose escalated too quickly
- Renal impairment
- Poor opioid responsive pain but escalated
- Has had intervention to reduce pain (nerve block)
Opioid toxicity presentation
- Pinpoint pupils
- Hallucinations, drowsiness
- Vomiting
- Confusion
- Myoclonic jerks
- Respiratory depression
management of opioid toxicity
naloxone
What do you need to know about safe opioid prescribing?
- Safe if administered and titrated appropriately
- How to prescribe morphine as IR and SR
- How to convert oral morphine to SC morphine
- There are conversion charts for changing to and from morphine – use these or ask advice
- Principles of how to use fentanyl patches
Stepping up Step 2 to Step 3 e.g. from maximum dose codeine to morphine
- Codeine:morphine is 10 : 1
-> 240mg (maximum dose per day) codeine equates to 24mg of morphine
-> TDD morphine = 24mg - So generally prescribe
->Morphine SR 15mg BD e.g. 15mg in morning and 15mg at night
-> plus also prescribe Morphine IR 5mg PRN
how morphine can be used
- Slow release (SR)
- Immediate release (IR)
All patients on regular (SR) opioids should have IR opioids for break through
immediate release (IR) morphine
Oromorph liquid 10mg/5ml (100mg/5ml)
Slow release (SR) morphine
- Zomorph capsule BD (10,30,60,w00,200mg)
- MST (morphine sulphate tablets) tablets BD (5,10,15,30,60,100,200mg)
Titration of opioid dose
1) Add up 24 hours worth of morphine = TOTAL DAILY DOSE (TDD)
2) TDD/2 = New Morphine SR dose
3) TDD/6 = New Morphine IR ‘breakthrough’ (PRN) dose
Morphine titration example:
Example 1
- Patient taking oromorph 5mg PRN
- Need 8 PRNs to achieve pain control
- Total Daily Dose (TDD) of morphine = 8 x 5= 40mg
- Change to SR morphine BD dose =40/2 = zomorph 20mg BD
- New PRN = 40/6 = oramorph 6mg PRN .
- …..often round down to 5mg
Morphine titration example:
Example 2:
- Patient taking zomorph 30mg BD
- But still some pain
- Needing 3 PRN doses a day of oramorph 10mg with good effect
- TDD = (30x2) +(3x10)
TDD= 90 - SR= 90/2 = 45mg BD
- IR= 90/6 = 15 PRN
Morphine titration example:
Example 3:
- Patient taking zomorph 120mg BD
- But still some pain
- Needing 3 PRN doses a day of oramorph 40mg with good effect
- TDD= (120x2) +(40x3)
-TDD= 360 - SR= 360/2= 180mg PRN
- IR= 360/6 = 60mg PRN
- New BD dose =360/2= zomorph 180mg BD
- New PRN = 360/6 = oramorph 60mg PRN
morphine and syringe driver
Oral vs subcut not the same
- Oral: SC 2:1
- Oral: IV 3:1
example 1 of morphine and syringe driver
- Morphine 40 mg/24 hours via syringe driver
- 5mg SC morphine PRN x4/24hr
- TDD = 40 +5+5+5+5 mg morphine subcut
- New dose in syringe driver=60mg
- PRN = TDD/6= 60/6= 10mg subcut
- Oral PRN would be oramorph 20mg (double SC due to oral:SC 2:1)
Rememeber
- Oral: SC 2:1
- Oral: IV 3:1
example 2 of morphine and syringe driver
- Current medication
- Morphine sulphate 60mg/24 hours via syringe driver
- PRN dose 10mg SC morphine prn
- needing 3 PRNs over 24hr
- TDD= 60mg (+3x10) = 90mg morphine via subcut route
- New background dose in syringe driver = 90mg
- New PRN. = TDD/6 = 90/6 = 15mg subcut
- Oral PRN would be 30 mg
Remember
- Oral: SC 2:1
- Oral: IV 3:1
fentanyl patches
- Transdermal opioid
- Non-renal excretion
- 12-24hr to achieve steady state
- Smallest patch is 12mcg/hr which equates to about 45mg (30-60mcg/hr) morphine in 24 hours
* Takes a while to get up to therapeutic level
*** Also need to wait to prescribe full dose of other opioid when switching because fentanyl lasts a few days after patch removal ** - Generally use oramorph as PRN (1/6th of 24 hour morphine equivalent)
what to be wary of with fentanyl patches
- Takes a while to get up to therapeutic level
- Also need to wait to prescribe full dose of other opioid when switching because fentanyl lasts a few days after patch removal
applying a fentanyl patch
- Needs to go on skin that’s not hairy
prescribing a controlled drug (CD)
CD prescription requirements
- Drug name
- Form e.g. modified release
- Drug strength
- Total amount of the drug in words and figures
–>This can be the total number of patches or bottles or tablets, it does NOT need to be the number of mg of the drug
–>E.g. supply 56 (fifty six) 10mg capsules
example morphine prescriptions
example prescription of fentanyl patches
example syringe driver prescription
which drug is good for liver pain
- Dexamethasone 8mg OD
A 55-year old male with end-stage pancreatic cancer was admitted to hospital due to decline in his condition. He took 50mg of regular oral morphine and 20mg oral for breakthrough pain yesterday. His medications have been changed to a syringe driver. What would the new prescription include?
Subcutaneous morphine 35mg over 24 hours in syringe driver
Subcutaneous morphine 70mg over 24 hours in syringe driver
IV morphine 35mg over 24 hours in syringe driver
Subcutaneous morphine 25mg over 24 hours in syringe driver
IV morphine 70mg over 24 hours in syringe driver
Subcutaneous morphine 35mg over 24 hours in syringe driver
The total daily dose required yesterday was 70mg of morphine orally. To convert to subcutaneous it would need to be divided by 2 = 35mg over 24 hours.
