Drugs Used in Chronic Non-Malignant Pain

NHSL Medicines Guidance
NHS Lanarkshire

General Notes

This section describes the management of chronic non-malignant pain in terms of the WHO Pain Ladder, as a stepwise approach to managing pain is sensible. However, it was not designed for the management of chronic pain and so prescribers should be mindful that management of chronic pain is often difficult and response to pharmacological treatments may be poor. Optimisation of analgesia at each step is important to avoid unnecessary polypharmacy.

There is limited evidence for the long-term use of opioids in the management of chronic non-malignant pain. Efficacy of opioids should be regularly reviewed following initiation or dose increase. If a 30% reduction in pain score or significant improvement in functional ability is not achieved, the opioid should be tapered and withdrawn.

The Commission on Human Medicines (CHM) has recommended that fentanyl transdermal patches are contraindicated in opioid-naive patients in the UK.  Other analgesics and other opioids should be used before prescribing fentanyl patches for non-cancer pain. Please see the MHRA Drug Safety Update (September 2020) for further information.

The Pain Assessment and Documentation Tool (PADT) can be used to assess baseline pain score and functional ability.

Step 1 Analgesics (Paracetamol +/-NSAID)

Preferred list (P)

PARACETAMOL

  • Consider dose reduction in patients with low body weight (<50kg), renal/hepatic impairment or glutathione deficiency (chronic malnourishment, chronic alcoholism) [NICE CKS].

IBUPROFEN

  • Doses greater than 1.2g daily are associated with increased risk of cardiovascular and gastro-intestinal adverse effects.

 

Total list (T)

NAPROXEN

Prescribing Notes:

In June 2013, the MHRA issued new guidance on the use of diclofenac following a review of cardiovascular risk.

The NICE CKS topic NSAIDS – prescribing issues provides further information on factors that should be considered when prescribing NSAIDs.

Step 2 Analgesics (Weak Opioid + Paracetamol +/-NSAID)

Preferred list (P)

CO-CODAMOL

Restrictions:

  • Co-codamol 15/500mg strength is non-formulary.

  • Dispersible and effervescent formulations should be restricted to patients with true swallowing difficulties. Their high sodium content (up to 8g daily) exceeds the WHO daily salt intake recommendation of 6g daily and may compromise the treatment of hypertension, heart failure and renal disease.

 

Total list (T)

CODEINE

  • Restriction: For use where flexible dosing is required and providing a combined product would result in administration of potentially unnecessary doses of codeine.

TRAMADOL

  • Restriction: Tramacet® (tramadol 37.5mg/paracetamol 325mg) is non-formulary and is not approved by the SMC for use within NHS Scotland.
  • Capsules are currently the most cost effective modified release formulation of tramadol.

Tramadol: Morphine Equivalence
(As per BNF online)

Preparation Total dose Oral morphine equivalence over 24 hours
Tramadol 50mg Capsules Two capsules four times a day (400mg) 40mg morphine daily
Tramadol MR Capsules 50mg One capsule twice a day (100mg) 10mg morphine daily
Tramadol MR Capsules 100mg One capsule twice a day (200mg) 20mg morphine daily
Tramadol MR Capsules 150mg One capsule twice a day (300mg) 30mg morphine daily
Tramadol MR Capsules 200mg One capsule twice a day (400mg) 40mg morphine daily

BUPRENORPHINE 7 day transdermal patch (Reletrans®)

  • It is recommended that buprenorphine patches are prescribed by brand name to reduce risk of confusion and error in dispensing and administration.

  • Reletrans® is the preferred brand of 7 day buprenorphine patch in NHS Lanarkshire.

Oral Morphine Equivalence
(As per BNF online)

Opioid Strength Oral morphine equivalence over 24 hours
Buprenorphine  5 micrograms/hr 7 day patch  12mg
Buprenorphine  10 micrograms/hr 7 day patch 24mg
Buprenorphine  15 micrograms/hr 7 day patch 36mg
Buprenorphine  20 micrograms/hr 7 day patch 48mg

Prescribing Notes:

Only one opioid should be prescribed at a time to optimise beneficial effects and minimise risk of adverse effects.

Codeine

  • At a daily dose of 240mg daily is equivalent to ~ 24mg of oral morphine.
  • Is an inefficient analgesic in some patients who are unable to convert it to morphine 
  • Equally, some patients may be extensive or ultra-rapid metabolisers and at an increased risk of developing side effects of opioid toxicity even at commonly prescribed doses.
  • For further information, see SPC (Section 4.4 Special Warnings and Precautions for Use)

Tramadol

  • Reclassified as a Schedule 3 Controlled Drug in 2014 following a significant increase in the number of deaths associated with its use.
  • Should be avoided in palliative care patients unless specifically requested by a Palliative Medicine Specialist.
  • Should be reserved for use in patients who have not had adequate pain relief with an optimised dose of codeine (60mg four times a day or highest tolerated dose) OR in whom constipation poses a major threat (e.g. after bowel surgery) OR who experience unacceptable sedation or respiratory depression with other opioids.

Step 3 Analgesics (Strong Opioid + Paracetamol +/-NSAID)

Preferred list (P)

MORPHINE sustained release (Zomorph®)

  • Sustained release preparations of morphine should be prescribed by brand name.

  • Zomorph® is currently the brand of choice within NHS Lanarkshire to ensure continuity between primary and secondary care settings.

    • In patients with true swallowing difficulties Zomorph® capsules can be opened and the contents mixed with semi-solid food (e.g. puree, jam, yoghurt).

    • The contents can also be suspended in water and administered via gastric or gastrostomy tubes of a diameter of more than 16 F.G. with an open distal end or lateral pores [SPC].

 

Total list (T)

OXYCODONE modified-release (Oxypro®)

  • Oxypro® is the preferred brand of modified-release (MR) oxycodone tablets in primary care in NHS Lanarkshire.
  • Restriction: for the management of chronic pain only where a patient cannot tolerate oral morphine despite treatment of associated side effects (e.g. constipation, nausea).

Oxypro®: Morphine Equivalence
(As per BNF online rounded to nearest 5mg)

Preparation Total Dose Oral morphine equivalence over 24 hours
Oxypro® 5mg tablets One tablet twice a day (10mg) 15mg morphine daily
Oxypro® 10mg tablets One tablet twice a day (20mg) 30mg morphine daily
Oxypro® 15mg tablets One tablet twice a day (30mg) 50mg morphine daily
Oxypro® 20mg tablets One tablet twice a day (40mg) 65mg morphine daily
Oxypro® 30mg tablets One tablet twice a day (60mg) 100mg morphine daily
Oxypro® 40mg tablets One tablet twice a day (80mg) 130mg morphine daily

FENTANYL 3 day (72 hour) transdermal patch (Mezolar Matrix®)

  • Restrictions:

    • Use only in patients requiring treatment with a strong opioid (>24mg daily) AND unable to swallow tablets/capsules OR have compliance issues due to cognitive impairment OR has problems with GI absorption.

    • 75 microgram and 100 microgram patches deliver more than 120mg oral morphine equivalence and therefore should only be initiated by a specialist.

  • It is recommended that fentanyl patches are prescribed by brand name to reduce risk of confusion and error in dispensing and administration.

    • Mezolar Matrix® is the preferred brand of 3 day (72 hour) fentanyl patch for use in NHS Lanarkshire.

  • The Commission on Human Medicines (CHM) has recommended that fentanyl transdermal patches are contraindicated in opioid-naïve patients in the UK.  Other analgesics and other opioids should be used before prescribing fentanyl patches for non-cancer pain.  Please see the MHRA Drug Safety Update (September 2020) for further information.

Oral Morphine Equivalence
(As per BNF online)

Opioid Strength Oral morphine equivalence over 24 hours
Fentanyl 12 micrograms/hr 3 day patch 30mg
Fentanyl 25 micrograms/hr 3 day patch 60mg
Fentanyl 50 micrograms/hr 3 day patch 120mg
Fentanyl 75 micrograms/hr 3 day patch 180mg
Fentanyl 100 micrograms/hr 3 day patch 240mg

Prescribing Notes:

  • Doses greater than 120mg oral morphine daily or equivalent should only be prescribed on the advice of a specialist as there is no evidence of increased benefit in the treatment of chronic non-malignant pain, but the risk of harm from adverse effects significantly increases [Quality Prescribing for Chronic Pain].
  • Patients taking regular opioids for chronic non-malignant pain should have a review every 6 months to monitor efficacy and adverse effects. A trial reduction in opioid dose should be considered to assess whether or not the current dose is still optimal.
  • Only one opioid should be prescribed at a time to optimise beneficial effects and minimise risk of adverse effects.
  • When switching between opioids the dose should be converted and the total daily dose reduced by at least 25%.
  • Immediate release opioids are more likely to be associated with intolerance and problem drug use.
  • There is unsatisfactory evidence to suggest that one strong opioid is more clinically effective than another. Therefore, if there is insufficient benefit obtained with one opioid, trial of an alternative opioid is not recommended. Consider referral to Pain Clinic.

NHSL Joint Adult Formulary Key

To indicate the category of a formulary medicine, updated sections adopt the following key:

Preferred list (P): First-line formulary choices.

Total list (T): Alternative choices when preferred list options not effective/not tolerated, or not indicated.

Specialist initiation (S1): Specialist initiation, or on the advice of a Consultant or Specialist Practitioner in this therapeutic area. Continuation in primary care is acceptable.

Specialist use only (S2): Supply via hospital, Homecare Service or a hospital based prescription (HBP) for dispensing by community pharmacy. Not prescribed in primary care setting.

Editorial Information

Last reviewed: 31/01/2022

Next review date: 31/01/2025

Author(s): NHSL.

Version: Please refer to the introduction section for an explanation of the review dates above.

Approved By: ADTC

Reviewer name(s): ADTC.