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Palliative

Prescribing - Pain LAURA BARNFIELD – 21/2/17

Aims

To understand the classes of painkillers available in palliative care

To gain confidence in counselling regarding opiates

To gain confidence prescribing opiate analgesia for different routes

of administration

To understand the concept of ‘total pain’

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WHO Pain Ladder

Paracetamol

Don’t underestimate this humble drug!

Great adjuvant to Codeine and Tramadol

Well-tolerated

Oral, rectal and IV routes

Dose adjustment for low weight- consider 1g tds/bd

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NSAIDs

Particularly useful in cancer patients with bony metastatic disease

(also consider referral for radiotherapy or asking hospice for advice

regarding bisphosphonates if struggling to control)

Consider an NSAID with a lower GI risk – Ibuprofen or Naproxen –

and consider PPI cover

Avoid in patients on steroids, caution with SSRIs, renal failure

Weak opiates

Consider in combination with Paracetamol –but think about cost –

Co-Codamol 15/500 very expensive

Consider opioids if intolerable side effects

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Neuropathic agents

Effective for neuropathic pain, but not for simply poorly controlled

chronic pain

Consider local prescribing guidance for which to start- which would

you choose?

Neuropathic agents

Treatment Pros Cons

Amitriptyline (TCA) 10mg-150mg Good NNT 2.1-3.6, can help with

mood or bladder spasm,

Dry mouth, sedation, falls risk in

elderly- postural hypotension

20% stop due to side effects

Gabapentin 100-300mg tds

increasing to 3600mg in divided

doses according to response

NNT 3.9-6.3, NNH 25

Cheap

Reduce dose in renal impairment,

takes some time for dose titration

Sedation, dizziness, ataxia

Pregabalin 25-75mg bd

increasing to 300mg bd – studies

on 150-600mg daily

NNT 7.7, relatively well tolerated,

bd dosing easier than

Gabapentin’s tds

On patent for neuropathic pain -

in GP setting meant to use Lyrica,

which is very expensive

Dose-response gradient 600mg

better than 300mg daily – but

caps on doses in GP setting

Sedation, dizziness, ataxia

Duloxetine (SNRI) 30-60mg od NNT 5.2, better tolerated than

TCAs

Delay to effect, nausea, dizziness,

drowsiness, sweating, dry mouth

In some areas

Lidocaine

patches might be

used – but these

are expensive

and only licensed

for post-herpetic

neuralgia

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Strong opiates WHY DON’T PATIENTS WANT TO TAKE THEM?

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Side effects

Constipation

Dry mouth

Nausea

Bloating

Hallucinations

Respiratory depression

Tolerance

Drowsiness

Dependence

Bradycardia

Tachycardia

Postural hypotension

Biliary spasm

Vertigo

Euphoria

Mood changes

Sleep disturbance

Urinary retention

Sweating

Flushing

Rash

Pruritus

Commencing opiates

Good practice is to prescribe for anticipated side effects by also

supplying laxatives (such as Laxido) and antiemetics (such as

Metoclopramide)

Stop weak opiates – do not prescribe multiple mixed opiates

Consider preferred route

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Conversions

Analgesic Route Dose

Morphine PO 10mg

Codeine PO 100mg

Tramadol PO 100mg

Oxycodone PO 5-6.6mg

Morphine IV/IM/SC 5mg

Diamorphine IV/IM/SC 3mg

Alfentanil SC 0.3mg

If someone has been taking regular full-dose Codeine, how much Morphine

would this be equivalent to?

Background need

Calculate appropriate dose from previous opiates (or from giving

Oramorph 5-10mg every 4hrs as needed) over 24hrs

Oral morphine preparations should be prescribed 12hrly (Zomorph,

MST) so divide 24hr dose by 2 for slow-release morphine dose for

background relief

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Breakthrough need

Divide 24hr morphine dose by 6 to establish breakthrough dose

If awkward number, always round down

This can be given 2-4hrly at home in the form of immediate-release

morphine (Oramorph, Sevredol)

If using more than 3 breakthrough doses in 24hrs regularly, consider

increasing background analgesia (usually by 30-50%, dependent on

breakthrough use)

Opiate Maths (1)

Kathy is 73 with metastatic breast cancer. She has been taking

regular Co-Codamol 30/500 TT qds but is still reporting breakthrough

pain

Please calculate an appropriate starting dose of Morphine for

Kathy, with both background and breakthrough analgesia. Show

your working.

Beryl is 68 with oesophageal cancer and has been taking Morphine

60mg bd, and 4x 20mg breakthrough Oramorph in 24hrs.

Please increase her background analgesia as appropriate, and

calculate her new breakthrough dose. Show your working.

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Alternatives to Morphine WHY MIGHT YOU USE OXYCODONE, DIAMORPHINE, ALFENTANIL,

BUPRENORPHINE OR FENTANYL?

Alternatives to Morphine

Oxycodone (Oxycontin/Oxynorm, Longtec/Shortec)– switch to if intolerable side effects, or reached dose-effect ceiling. Better in renal failure.

Diamorphine- used sub-cut when large doses required- comes as powder so can be made up to a small volume at higher concentration

Alfentanil- used in severe renal impairment- unlikely to be used in the community setting

Buprenorphine- for patients who prefer/require transdermal route for weak opiate doses

Fentanyl- for patients who prefer/require transdermal route for strong opiate doses

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Opiate Maths (2)

Hugo has been taking Zomorph 80mg bd and in the last few days is

using 2x breakthrough doses of 25mg Oramorph. He is getting

significant side effects of hallucinations, jerkiness but is still in pain.

What do you want to know?

What will you prescribe?

Jennifer is using a 50mcg Fentanyl patch that she has started just 10

days ago. The hospital did not supply her with breakthrough

analgesia and she is reporting pain mostly in the evenings.

What would you prescribe?

Subcutaneous infusions

CSCI (continuous subcutaneous infusion) is the preferred method of

administration of medication at the end of life because of ease of

access, steady dose and loss of oral route.

Why do we not use Fentanyl patches routinely in this situation?

Morphine and Oxycodone are the most commonly used analgesics.

If someone is using one of these and loses their oral route, continue

with the same medication in the infusion.

The subcutaneous dose is found by calculating the oral dose over

24hrs (may include breakthrough doses) and dividing by two

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Opiate Maths (3)

Kenneth has been taking 100mg Zomorph bd for several weeks for pain from his prostate cancer. He is reaching end of life and now unable to swallow. In the last 2 days he has averaged 3x breakthrough doses in 24hrs of 30mg Oramorph.

What would you put in his CSCI? Show your working.

What would you prescribe for breakthrough use?

Ethel has been taking 35mg bd of Oxycontin and averaging 2 breakthrough doses of 10mg Oxynorm daily for her metastatic ovarian cancer. She can no longer tolerate oral medications as she has developed bowel obstruction.

What would you put in her CSCI? Show your working.

What would you prescribe for breakthrough use?

Fentanyl Patches at End of Life

If a patient has a Fentanyl patch on already LEAVE THIS IN PLACE

AND CHANGE AS USUAL

A CSCI of Morphine or Oxycodone can be added to a Fentanyl

patch for quicker titration of analgesic need – please ensure this is

an adequate dose. Double the PRN dose would be a good place

to start.

Do not increase the patch in the last days of life

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Opiate Maths (4)

William is 84 and dying from pancreatic cancer. He has been

wearing a Fentanyl patch at 100mcg. The dose was last increased

4 weeks ago. He is now unable to take oral medication and is

appearing in pain.

What would you prescribe for background pain relief?

What would you prescribe for breakthrough? Show your workings.

Total Pain Assessment

This is a useful tool to consider your patient holistically- particularly

when they have rapidly escalating analgesic requirements or

difficult to manage pain that doesn’t respond to traditional

analgesia.

Consider the patient’s pain from Physical, Psychological, Spiritual

and Social perspectives- is there anything you (or another

professional) can do to reduce their pain and distress other than

increasing opiates?

Example- 49yr old hospice patient with lung cancer and treatment-

resistent hypercalcaemia

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Conclusion

You are not restricted to using just opiates in palliative care- consider adjuncts, and for bone metastases in particular alternatives are more effective. Always ask ‘does the pain get better when you take your opiates?’

Write all calculations longhand and consider getting someone else to check them before prescribing. If in doubt, seek help, and always round down.

If reaching end of life, convert to a CSCI using the opiate they are already using – and never mix opiates

Keep the Fentanyl patch on and replace as usual, but do not use this to rapidly titrate analgesia

Consider a total pain assessment if struggling to control a patient’s pain

References

Pain and Symptom Control Guidelines Greater Manchester Strategic

Clinical Network, revised August 2016

Palliativedrugs.com

NICE evidence – Pain and Opiate Analgesia