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Scottish Palliative Care Guidelines print pdf

Choosing and Changing Opioids


Introduction

Opioids are used for pain and breathlessness. Most palliative care patients respond well to titrated oral morphine:

  • For frail/elderly patients, consider a lower starting dose of opioid.
  • Seek specialist advice if the patient is in moderate to severe pain with frequent use of breakthrough medication, ie more than three doses in 24 hours.

A small number of patients may need to be changed to another opioid if:

  • oral route is not available
  • pain is responding but the patient has persistent intolerable side effects (consider reducing the dose and titrating more slowly or adding an adjuvant analgesic before changing opioid)
  • moderate to severe liver or renal impairment
  • poor compliance with oral medication
  • complex pain (consider adjuvant analgesics/other pain treatments).

Preparations

Choosing an opioid for moderate to severe pain

First-line opioids (see Pain management guideline)
Morphine
  • Range of oral preparations available; subcutaneous (SC) injection and in a CME T34 syringe pump.
  • Renally excreted, active metabolites – titrate morphine slowly and monitor carefully in stage 1 to 3 chronic kidney disease.
  • Consider other opioids in stage 4 to 5 chronic kidney disease, dialysis patients.
  • Consider low doses and slow titration in liver impairment.
Diamorphine
  • Highly soluble opioid used for SC injection and in a CME T34 syringe pump.
  • Use for high-dose SC breakthrough injections (above 180mg SC morphine/24 hours). Powder preparation is diluted in a small volume of water for injections.
  • As with morphine, cautious use in renal and liver impairment.
Second-line opioids
Oxycodone
  • For moderate to severe pain if morphine/diamorphine are not tolerated.
  • Immediate and modified release oral preparations (ensure correct preparation is prescribed); SC injection; CME T34 syringe pump.
  • Lower concentration preparation limits dose for SC injection to 20mg (2ml). (In some health boards, a 50mg/ml injection is available – check local guidance).
  • Avoid in moderate to severe liver impairment, clearance is much reduced.
  • Mild to moderate renal impairment: reduced clearance so titrate slowly and monitor carefully. Avoid in stage 4–5 chronic kidney disease.
Fentanyl (see fentanyl patches guideline)
  • Transdermal patch lasting 72 hours; use if oral and SC routes are unsuitable.
  • For stable pain if morphine not tolerated; dose cannot be changed quickly.
  • No initial dose reduction in renal impairment but may accumulate over time.
  • Liver impairment; dose reduction may be needed in severe liver disease.
  • Do not initiate at the end-of-life when the oral route is no longer available (can take too long to reach steady state) – see Fentanyl patch guideline. If a patient is already on a fentanyl patch and in the last days of life, see Fentanyl patch guideline.
Third-line opioids (seek specialist advice)
Alfentanil
  • Short-acting, injectable opioid for SC injection and in a CME T34 syringe pump.
  • In episodic/incident pain, it can be given sublingually (an unlicensed spray is available) or subcutaneously.
  • Dose does not need to be reduced in renal disease including stage 4–5 chronic kidney disease.
  • Clearance may be reduced in liver impairment; reduce dose and titrate.
Fentanyl sublingual/intranasal
Fourth-line opioid (specialist use only)
Methadone
  • Oral methadone is used by specialists for complex pain; dosing is difficult due to the long half life; no renal excretion so no dose reduction required in chronic kidney disease, half life prolonged in severe liver disease.

Cautions

Opioid toxicity

  • Wide variation in the dose of opioid that causes symptoms of toxicity.
  • Prompt recognition and treatment are needed. Symptoms include:
    • persistent sedation (exclude other causes)
    • vivid dreams/hallucinations; shadows at the edge of visual field
    • delirium
    • muscle twitching/myoclonus/jerking
    • abnormal skin sensitivity to touch.
  • Reduce the opioid by a third if pain is controlled. Ensure the patient is well hydrated. Seek advice.
  • Consider adjuvant analgesics, alternative opioids or both if patient still in pain.
  • Naloxone (in small titrated doses) is only needed for life-threatening respiratory depression. See Naloxone guideline)

Dose and Administration

Changing opioid

  • These doses/ratios are approximate (≈) and should be used as a guide.
  • Dose conversions should be conservative and doses are usually rounded down.
  • Monitor closely; extra care if frail, elderly patient; renal or hepatic impairment.
  • Always prescribe an appropriate drug and dose for breakthrough pain:
    • one-tenth to one-sixth of the 24-hour regular opioid dose as required.

 

Table 1: Conversions from weak oral opioids to oral morphine

table 1

Weak oral opioid dose

Equivalent oral morphine dose

Conversion factor from weak oral opioid to morphine

Oral codeine 60mg or oral dihydrocodeine 60mg

≈Oral morphine 5mg

Divide by 10

Oral tramadol 50mg *

≈Oral morphine 5 to 10mg

Divide by 5 to 10

Oral nefopam 30mg *

≈Oral morphine 10mg

Divide by 3

Choosing and changing opioids in palliative care Table 1. Version 2 March 2015

  

Table 2: Conversions from oral morphine to other strong opioids

table 2

Oral morphine dose

Equivalent opioid dose

Conversion factor from oral morphine to other opioid

Oral morphine 10mg

≈SC morphine 5mg

Divide by 2

Oral morphine 10mg

≈SC diamorphine 3mg

Divide by 3

Oral morphine 10mg

≈Oral oxycodone 5mg

Divide by 2

Oral morphine 10mg

≈SC oxycodone 2 to 3mg

Divide by 4

Oral morphine 60 to 90mg

≈Fentanyl patch 25 microgram/hour

See: Fentanyl

Oral morphine 30mg

≈SC alfentanil 1mg (1000micrograms)

Divide by 30 See: Alfentanil

Oral morphine 5 to 10mg

≈Oral hydromorphone 1.3mg*

Divide by 5 to 7.5

Immediate release oxycodone

Conversion factor from oral to SC

Oral oxycodone 5mg

≈SC oxycodone 2 to 3mg

Divide by 2

Choosing and changing opioids in palliative care Table 2. Version 3 March 2014

*Not generally recommended for use in palliative care

For advice on use of buprenorphine patches* (BuTrans® 5, 10 & 20mcg/hr - 7 day patch) and (Transtec® 35, 52.5 & 70mcg/hr - 4 day patch) seek specialist advice.

Dose Conversions

A guide to dose conversions from morphine to second-line opioid analgesics used for moderate to severe pain

  • Use Table 3 as a guide. The doses are approximate (≈) and not exact equivalent doses.
  • Opioid bioavailability (particularly for oral morphine) and response are highly variable.
  • Always prescribe an appropriate drug and dose for breakthrough pain: one-tenth to one-sixth of the 24-hour regular opioid dose as required.
  • Reduce the dose by up to 30% when changing opioid if the patient is opioid toxic, frail or elderly and re-titrate.
  • Reduce the dose by up to 30% when converting from a second-line opioid back to morphine and re-titrate.
  • Check the information about individual drugs if the patient has renal or liver impairment.
  • Particular care is needed when changing between opioids at higher doses or when the dose of the first opioid has been rapidly increased as these patients are at greater risk of adverse effects.
  • Morphine and oxycodone doses can be measured accurately in 1mg dose increments. Decimal places are not recommended.
  • Fentanyl: Check Fentanyl patches guideline for dose.
  • Alfentanil: Check Alfentanil guideline for dose conversions.

Monitor the patient carefully. If in doubt, seek advice.

 

Table 3 - A guide to dose conversions from morphine to second line opioid analgesics used for moderate to severe pain.

Use this table as a guide. The doses are approximate and not exact equivalent doses. The 4 hour breakthrough opioid doses are based on a calculation of one sixth of the daily dose- these doses may be adjusted up or down to avoid the use of decimal points and to allow a practical dose to be administered. Some patients may require a smaller 4 hour breakthrough dose of one tenth of the daily dose. Initiate dose with caution depending upon clinical condition and judgement.

Table 3

Table 3. A guide to dose conversions from morphine to second-line opioid analgesics used for moderate to severe pain

Oral morphine

Subcutaneous morphine

Subcutaneous diamorphine

Oral oxycodone

Subcutaneous
oxycodone

4-hour dose

12-hour
MR dose

24-hour total dose

4-hour dose

24-hour
total dose

4-hour dose

24-hour total dose

4-hour dose

12-hour
MR dose

24-hour total dose

4-hour dose

24-hour total dose

2 or 3mg

5mg

15mg

1mg

7 or 8mg

1mg

5mg

1 or 2mg

-

7 or 8mg

1mg

5mg

5mg

15mg

30mg

2 or 3mg

15mg

2mg

10mg

2 or 3mg

5mg

15mg

1mg

7 or 8mg

10mg

30mg

60mg

5mg

30mg

3mg

20mg

5mg

15mg

30mg

2 or 3mg

15mg

15mg

45mg

90mg

7 or 8mg

45mg

5mg

30mg

7 or 8mg

20mg

45mg

3mg

20mg

20mg

60mg

120mg

10mg

60mg

7mg

40mg

10mg

30mg

60mg

5mg

30mg

30mg

90mg

180mg

15mg

90mg

10mg

60mg

15mg

45mg

90mg

7 or 8mg

45mg

40mg

120mg

240mg

20mg

120mg

10mg

80mg

20mg

60mg

120mg

10mg*

60mg

50mg

150mg

300mg

25mg

150mg

15mg

100mg

25mg

75mg

150mg

*

75mg

60mg

180mg

360mg

30mg*

180mg

20mg

120mg

30mg

90mg

180mg

*

90mg

MR = modified release (long acting)
*Morphine injection is available in a maximum concentration of 30mg/ml. Oxycodone injection may only be available as 10mg/ml (50mg/ml injection may be available in some health boards). Another SC opioid will be needed for breakthrough pain if patient needs a dose that is in an injection volume above 1ml – Seek advice.
Choosing and changing opioids in palliative care Table 3. Version 3a Nov 2014