Buku Medicine

Overview

Quick Tip: Some types of pain do not respond well to opioids and require adjuvant analgesics  

These drugs are safe, effective and appropriate in palliative care provided that clinicians: 

  • Start and titrate opioids cautiously 
  • Remember different opioids have different properties and potencies 
  • Monitor and manage adverse effects caused by opioids 

The place for opioids in pain management may be guided by a step-wise approach (such as the traditional WHO “analgesic ladder”), moving up the steps if pain control is not achieved. 

STEP 1 

Non-opioid (Paracetamol and/or NSAID) +/- adjuvant 

STEP 2 

Opioid for mild to moderate pain* +/- non-opioid (Paracetamol and/or NSAID) +/- adjuvant 

(* e.g. codeine, dihydrocodeine, tramadol) 

STEP 3 

Opioid for moderate to severe pain* +/- non-opioid (Paracetamol and/or NSAID) +/- adjuvant 

(* e.g. morphine, oxycodone, fentanyl) 

 

NCA handbook

http://www.northerncanceralliance.nhs.uk/wp-content/uploads/2018/11/NECNXPALLIATIVEXCAREX2016.pdf 

 

Different opioids

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Changing routes

Quick Tip: Guidance varies depending on whether the oral opioid is Immediate Release (IR) or Modified Release 

 

Oral to subcutaneous infusion 

From IR opioid: start syringe driver immediately. 

From 12-hrly MR opioid: start syringe driver 2 hours before next oral dose would have been due. 

 

Subcutaneous infusion to oral 

Switching to either IR or MR opioid, stop the syringe driver and give first oral dose at the same time. 

 

Oral to patch 

From IR opioid: apply patch when convenient and use oral IR opioid as required. 

From twice daily MR opioid: apply patch at same time as last dose of MR oral opioid. 

(From once daily MR opioid: apply patch 12 hours after last dose of MR opioid). 

 

Patch to oral 

Remove patch 6 hours before giving first dose of oral MR opioid. 

For first 24 hours (i.e. first two doses) give HALF the calculated equivalent dose since the transdermal opioid will take time to be cleared from plasma and subcutaneous reservoir. 

After 24 hours, increase to the calculated equivalent dose if clinically indicated by pain. 

 

Patch to subcutaneous infusion 

If the patient is thought to be in the last hours to days of life, leave the patch in place and continue to change it at the right time intervals, and add a syringe driver with injectable medication alongside to make up the additional opioid treatment needed. 

In other situations where a change from patch is required, remove patch and start syringe driver 6 hours later using HALF the calculated opioid equivalent dose for the first 24 hours then adjust according to symptom control and the need for breakthrough analgesia. 

 

Subcutaneous infusion to patch 

Apply patch. Continue subcutaneous infusion for a further 6 hours then discontinue syringe driver. 

 

NCA handbook

http://www.northerncanceralliance.nhs.uk/wp-content/uploads/2018/11/NECNXPALLIATIVEXCAREX2016.pdf 

 

Opioid titration

Quick Tip: Morphine is the first line WHO step 3 opioid of choice 

 

Key tips  

  • Initiation and titration may use Immediate Release (IR) or Modified Release (MR) formulations 
  • Ensure the breakthrough dose is 1/6th – 1/10th of the total daily opioid dose  
  • Prescribe regular laxative (ongoing), and regular or ‘as required’ anti-emetic (for 1 week) 
  • Monitor closely for efficacy, adverse effects and toxicity 
  • Make patients aware of driving regulations when on opioids (https://www.gov.uk/drug-driving-law) 
  • If the pain is severe and rapid dose titration seems necessary, seek specialist advice
  • For safety, do not increase regular doses of MR opioid by more than 30-50% every 2 days

Breakthrough doses of opioids 

  • Pain occurring despite regular opioid (breakthrough pain) is treated with an immediate release (IR) formulation of the same opioid where possible
  • The breakthrough dose is usually between 1/10th and 1/6th of the total 24hr dose
  • IR opioids usually have onset of action within 30 minutes and last 3-4hrs at most
  • A common starting point is to prescribe 1/6th of the total 24hr dose (using a practical dose, rounding down rather than up) to be given 2-hourly as required and adjusted according to benefit and tolerability  
  • Setting a daily maximum number of breakthrough doses (e.g. 6 in 24hrs) should prompt review of a patient whose pain is out of control
  • Severe, refractory or rapidly recurring pain may require higher doses than 1/6th of the daily amount, and/or repeating sooner than 2 hours
  • It is best to avoid repeating within 1 hour in case delayed absorption results in rapidly accumulating doses 

 

NCA handbook

http://www.northerncanceralliance.nhs.uk/wp-content/uploads/2018/11/NECNXPALLIATIVEXCAREX2016.pdf 

 

Opioid titration diagram

Opioid conversion

Quick Tip: If the opioid switch is because of opioid toxicity, check the eGFR and seek specialist advice on opioid choice and dose. Breakthrough doses may be needed to cover transition periods.  

Moving from an opioid for moderate pain to an opioid for severe pain  

  • Codeine 240mg/24hrs is equivalent to oral morphine 24mg/24hrs  
  • Because some patients do not metabolise codeine normally cautious conversion is advised 
  • Tramadol 400mg/24hrs is considered equivalent to oral morphine 40mg/24hrs. 

 

NCA handbook

http://www.northerncanceralliance.nhs.uk/wp-content/uploads/2018/11/NECNXPALLIATIVEXCAREX2016.pdf 

 

Opioid conversion table

Common concerns

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Adverse effects

Quick Tip: Side effects are different from opioid toxicity. Constipation and dry mouth are lasting side effects of morphine, whereas nausea and vomiting and sedation often settle within days.  

 

Side Effects 

  • Constipation – common, persists, worse with dose increase.  Prescribe stimulant laxative (e.g. senna) adding a softener if needed (e.g. docusate).  
  • Nausea/vomiting – common when starting, usually settles within days.  Prescribe anti-emetic ‘as required’ (e.g. haloperidol 0.5-1.5mg nocte or metoclopramide 10mg tds) for the first week, titrating to response. 
  • Sedation – fairly common during early days of treatment, then often settles.  Reassure patient unless severe or cognitive impairment.  Consider dose reduction, alternative analgesic or seek advice on opioid switch. 
  • Dry mouth – common and persistent.  Ensure good oral hygiene.  Consider saliva stimulants (e.g. pilocarpine) or artificial saliva (e.g. Biotene or Bioextra gel). 

 

Opioid toxicity (for Emergency Treatment see Emergencies) 

Features: myoclonic jerks, pin-point pupils, hallucination, confusion, reduced respiratory rate.  Reduce opioid dose by 30-50%. Check renal function. Seek specialist advice on alternative analgesics or opioid switch. 

 

NCA handbook

http://www.northerncanceralliance.nhs.uk/wp-content/uploads/2018/11/NECNXPALLIATIVEXCAREX2016.pdf