Conversions of Strong Opiates
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Transcript Conversions of Strong Opiates
Common issues:
Opioid Prescribing and LCP
GP Clinical Governance Meeting
13th of July 2011
Dr Marion Lieth
Consultant in Palliative Medicine, Bolton Hospital
and Bolton Hospice
Outline
Common things about opioids:
Some basics about prescribing opioids
Common side effects and how to deal with them
Fentanyl patch
Opioid switch
Care of the dying
Case scenarios for discussion – Prescribing for LCP
Strong Opiates Used in Palliative
Care
Morphine (oral, subcut)
Oxycodone (oral, subcut)
Diamorphine ( subcut)
Fentanyl (transdermal, buccal, transmucosal)
Alfentanyl (subcut)
Hydromorphone (oral, subcut)
Buprenorphine (transdermal)
Methadone
Some basics about opioids
All strong opiates provide effective analgesia
All have the same potential side effects.
Tolerated differently by different patients depending upon the
dose required and coexisting factors eg renal function
Use oral route if possible
Morphine is 1st line
Start small, give regularly, review often and titrate
NPSA alert – max 30-50% increase
Patient factors, pain intensity, side-effects
PRN dose depends on total 24 hour dose
In general 1/6th
Provide explanations and deal with concerns
Common side effects
Nausea and vomiting
often in the first days, occasionally persistent
Metoclopramide or haloperidol
Constipation
Stimulant + softener laxative
A sense of drowsiness, often improves after a few days
Confusion (particularly the elderly)
Small initial dose and titrate slowly, check renal function, warn
the patient
Neurotoxic side effects
Hallucinations
Bad dreams
Myoclonus
Delirium
Drowsiness
Dose and patient dependent
Poor renal function
Check RF, reduce dose, switch opioid
Serious side effects
Drug dependence:
common fear
rare if prescribed and used properly
Respiratory depression:
Rare if prescribing guidelines are followed
Fentanyl patch
Not better then any other opioid
Non-oral route
E.g. Head and neck cancers
Useful in renal failure
Compliance
Slow to titrate
Not good for acute or unstable pain
Potent analgesic
Fentanyl 25mcg her hour = ???
oral Morphine over 24 hrs
Fentanyl patch
Not better then any other opioid
Non-oral route
E.g. Head and neck cancers
Useful in renal failure
Compliance
Slow to titrate
Not good for acute or unstable pain
Potent analgesic
Fentanyl 25mcg her hour = 60-90mg oral Morphine over 24 hrs
Codeine 240mg a day = ???? oral Morphine over 24 hours
Fentanyl patch
Not better then any other opioid
Non-oral route
E.g. Head and neck cancers
Useful in renal failure
Compliance
Slow to titrate
Not good for acute or unstable pain
Potent analgesic
Fentanyl 25mcg her hour = 60-90mg oral Morphine over 24 hrs
Codeine 240mg a day = 24mg oral Morphine over 24 hours
Opioid switch – Reasons:
One opioid does not work better then other
Patient preference
Problems with route of administration
Side effects; intolerable, dose limiting
Renal failure
Volume of injection
Principles of Conversions
Convert for the right reasons
Confirm the analgesia used so far
Don’t guess, use tables and calculations
Tables are only a guide – if high doses convert conservatively
and titrate
Review the outcome of the drug change and adjust the dose
if necessary
Basic Conversions
Potency
oral codeine
oral morphine
oral morphine
sc morphine
oral morphine
oral Oxycodone
oral oxycodone
sc oxycodone
oral morphine
sc diamorphine
Fentanyl patch 25mcg/hour is equivalent to about ??? mg of
oral morphine per day.
Basic Conversions
Potency
oral codeine
oral morphine
1:10
oral morphine
sc morphine
1:2
oral morphine
oral Oxycodone
1:2
oral oxycodone
sc oxycodone
1:2
oral morphine
sc diamorphine
1:3
Fentanyl patch 25mcg is equivalent to about 60-90 mg of oral
morphine per day.
Analgesia when patient is dying
If analgesia hasn’t been required so far
prescribe morphine 2.5- 5mg sc prn
If on regular strong opioids by mouth
Convert regular long-acting opioid dose to sc
sc Morphine if on oral morphine
sc Oxycodone if on oral oxycodone
divide the oral dose by 2
Timing?
Prescribe PRN (a sixth of 24hr dose)
Fentanyl patches and syringe
drivers
Continue the fentanyl patch
Write up PRN opioid dose
If in pain:
Add morphine or oxycodone to the syringe driver
‘Rule of thumb’ – start syringe driver with 2x prn dose over 24
hours = 30% increase
Recalculate PRN dose
Fenanyl patch + syringe driver
Any questions?
Q 1.
A district nurse contacts you to suggest a patient is started
on the LCP.
The patient has been taking 90mg of morphine MR bd and
two additional doses of morphine soln 30mg each day.
How would you respond to this and what do you prescribe?
Answer 1.
Why does she think that the patient is dying? Check history,
drugs, exclude reversible factors
Has pain been well controlled on the oral morphine?
If you think a syringe driver is required and depending on
above and your assessment:
MST 90mg bd + Oramporph 30mgx2
240mg oral morphine per day
120mg morphine sc/24hrs
20mg morphine sc prn
Q2
A district nurse contacts you to suggest a patient is started
on the LCP.
The patient has been taking 200mg Oxycontin bd and the
pain has been well controlled on this. There are no reversible
factors, the patient is dying and unable to swallow.
What do you prescribe?
Answer 2
Switch to sc infusion
Oxycontin 200mg bd
Oral Oxycodone 400mg over 24 hours
Oxycodone 200mg sc over 24 hours
Concentration in ampule:
Oxycodone 10mg/ml
20 ml
Maximum volume in syringe driver?
20ml syringe holds 16-17ml
30ml syringe holds 22ml
Answer 2
3 options:
Why Oxycodone?
Use 30ml syringe, e.g. holds 22ml – but little volume left for
other drugs
2. Switch to Diamorphine
1.
Oral Oxycodone 400mg/24 hours
Oral Morphine 800mg/24 hours
Sc Diamorphine 800 divided by 3 = 260mg sc Diamorphine /24 hours
Ring Hospice advice line
3.
Confirm numbers
Other options – e.g Alfentanyl
Q3
A patient started on a fentanyl patch only last week. The dose
is now 50mcg. The patient continues to have pain and needs
prn morphine 10mg every 2 hours or so.
The district nurse requests review. She thinks a syringe driver
is indicated.
What do you suggest?
Answer 3
What about the pain? does the prn morphine help? Prn
dose appropriate? Can patient take oral Morphine? Is the
oral morphine absorbed? How many prn doses exactly?
Are there other causes of distress? Is the patient opioid
toxic?
Try appropriate PRN Morphine dose – 30mg oral, 15mg
sc morphine
Use of syringe driver and dose depends on these answers
If able to take by mouth – regular oral Morphine
Morphine sc 30-60mg/24 hr could be reasonable.
Continue the patch
Q4
A patient has a fentanyl patch 75mcg in place and 60mg
morphine in a syringe driver.
What is the correct prn dose of morphine?
Answer 4
The prn dose should be calculated by thinking about both the
patch and the morphine infusion, ie the total 24 hr dose of
opiate
3 Different ways:
1. PRN for each and add together:
Fentanyl patch 75mcg/hr
prn oral morphine 40mg
prn sc morphine 20mg
Morphine sc infusion 60mg/24h
prn 10mg sc morphine
Therefore: PRN sc morphine 20+10 = 30mg
Answer 4
Convert to total oral daily dose, then PRN for total
Fentanyl patch 75mcg/hour
equivalent oral Morphine 270mg/24hours
Morphine sc infusion 60mg/24 hours
Equivalent oral Morphine 120mg/24hours
Total equivalent oral Morphine dose 390mg/24hours
PRN oral Morphine 60mg
PRN sc Morphine 30mg
2.
3.
Ring a friend
Bolton Hospice Advice line – 01204 663066
Q5
You have seen a patient who you think is dying. After discussion
with the family and district nurse you commence the LCP.
The patient normally takes Oxycodone 30mg bd and Cyclizine
50mg tds. His symptoms are well controlled on this.
What do you prescribe?
Answer 5
Switch regular Oxycontin to syringe driver
Continue regular anti-emetic
Anticipatory prescribing for other common symptoms of
dying patient – PRN medication
Pain
Nausea
Respiratory secretions
Distress/Agitation
Breathlessness
Answer 5
This patient is on Oxycontin 30mg bd, Cyclizine 50mg tds
Syringe driver:
Oxycodone 30mg sc infusion over 24 hours
Oxycodone and Cyclizine are not compatible in syringe
Levomepromazine 6.25-12.5 mg sc infusion over 24 hours
Anticipatory PRN medication:
Oxycodone 5mg sc
Levomepromazine 6.25mg sc 4-6 hourly
Hyoscine hydrobromide 400microgram sc
Be aware – similar name – Hyoscine butylbromide (Buscopan)
Midazolam 2.5 -5 mg sc, max 20mg over 24 hour
If requires more – needs review
Advice
Guidelines
Conversion charts
The palliative care team are always happy to help
Bolton hospice advice service Tel 663066
New syringe drivers
Recent NPSA alert
In Bolton acute hospital, community services and hospice
have switched from Graesby pumps to McKinley T34 syring
drivers on 15th of June 2011
Nursing staff have been trained in new device
No difference for prescribing
Maximum volume remains unchanged
17ml in 20 ml syringe
22ml in 30 ml syringe