Points about pain with people with cancer
• The assessment of pain is part of the holistic care of the patient
• 30% of people with cancer have no pain
• Those with pain often have several types. A patient who feels cared for may feel less pain
• A patient free from pain is better placed to face his/her illness
• Cancer pain can be well controlled in 95% of patients. If the patient’s pain appears not to respond, consider alternative causes of pain (spiritual, social or psychological factors). Cancer pain may also be related to debility e.g. pressure ulcers
• Patient and carer understanding of the use of their medication is vitally important in achieving good pain control
Is it a cancer related pain? If so consider four main types:
1. Visceral/soft tissue pain
• opioid sensitive – use the “ladder” (see below)
2. Bone pain
• NSAID sensitive
• partly opioid sensitive
• radiotherapy may help
3. Nerve related
• partly opioid sensitive
• adjuvant analgesics may often be needed (see adjuvant analgesics)
4. Incident pain
• e.g. exacerbations of pain on movement, may require fast acting analgesia
Many pains are not cancer related but may be:
• Treatment related e.g. constipation, post radiotherapy
• Coincident illness or condition e.g. arthritis, migraine
STEP 1: PARACETAMOL AND NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (see Adjuvant Analgesia)
Dose: 500mg – 1g, 4–6 hourly. Max dose 4g in 24 hours
Dispersible tablets: 500mg.
Oral suspension: 250mg in 5ml. Suppositories: 500mg
Injection for IV infusion: 10mg/ml, 50ml
(500mg) and 100ml (1g) vials
Non–steroidal anti-inflammatories – NSAIDs
Indications: for analgesia in palliative care, including action as adjuvant analgesic
1. Bone pain
2. Soft tissue pain due to malignant infiltration
4. Possible role in early management of neuropathic pain
• Assess analgesic response after regular use for one week
• Patients considered to be at risk of NSAID induced gastroduodenal ulceration (age over 65 years, past history of PUD, concomitant oral steroids or anticoagulants, serious comorbidity1) should receive a gastro-protective drug such as proton pump inhibitor
• Use with extreme caution in renal failure. Fluid retention and renal function may all be worsened by NSAIDs. There is little evidence to suggest that any particular NSAID is safer than another in respect of renal toxicity
• NSAIDs may be considered for asthmatic patients unless they have a history of aspirin sensitivity
STEP 2 : WEAK OPIOIDS (FOR MODERATE PAIN)
e.g. codeine, dihydrocodeine, tramadol, buprenorphine as ‘BuTrans’ patches
These opioids have low potency but can be a useful second step for patients with moderate pain. For approximate doses of opioids in chronic usage see Relative doses of opioids.
It is seldom useful to change from one preparation to another (unless to alter side effects). If regular doses do not provide adequate analgesia, move up the ladder to step 3. Compound preparations of paracetamol and weak opioids maybe useful. Only preparations with higher doses of opioids (codeine 30mg,dihydrocodeine 20-30mg) should be used, as the lower strength preparations produce opioid side effects with little analgesia.
For analgesic equivalence see conversion table and Relative doses of opiods
STEP 3: STRONG OPIOIDS (FOR MODERATE TO SEVERE PAIN)
First line: Morphine remains the drug of choice
1. Gain Control of Pain.
• ‘Immediate’ release morphine (elixir or tablets) gives greatest flexibility for dose titration
Starting dose 5mg–10mg four-hourly
(5mg for opioid naïve patients)
i.e. 6 x daily,
Additional p.r.n. doses at the same starting dose may be prescribed up to hourly.
Review the total daily dose of morphine every 24 hours. Titrate the dose to achieve pain relief by increasing in 30–50% increments per day3,4
In the elderly or those with renal impairment use smaller doses e.g. 2.5mg four-hourly, with close monitoring (see Symptom control in patients with renal disease and cardiac failure)
Reassess pain control daily
• A ‘log’ of treatment kept by patients and carers is helpful in titration
• There is no ‘maximum’ dose if pain is morphine responsive
• Specialist palliative care advice should be sought in the following circumstances:
• rapidly escalating dose of morphine
• morphine exceeds 300mg in 24 hours
• if the patient develops adverse effects e.g. opioid toxicity (signs are respiratory depression, increasing drowsiness, confusion, myoclonic jerks)
• In patients with less severe pain, or where circumstances dictate, morphine may be initiated as a modified release preparation at the appropriate dose. Use conversion table (see Relative doses of opioids) to determine the appropriate starting dose
Always prescribe a laxative when initiating opioid and continue to review bowel habit. See side effects.
Once pain is controlled there is a choice of options for maintenance.
– Continue regular immediate release morphine.
– Change to 12 hourly modified release morphine.
• A patient should never be prescribed more than one modified release opioid at a time
Patients on modified release opioids should always have available immediate release opioid prescribed p.r.n. for episodes of breakthrough pain.
• The recommended dose of immediate release opioid (usually morphine) prescribed p.r.n. for breakthrough pain is the equivalent of up to 1/6th of the total 24-hour opioid dose
• If the regular dose of opioid is increased, ensure that the p.r.n. breakthrough dose is increased appropriately so that it remains 1/6th of the total daily dose of regular opioid
• Incident pain (e.g. exacerbations of pain on movement) may require faster acting analgesia (see Incident pain )
• Ensure patients and their carers understand the use of the opioids they are taking and that doses are reviewed regularly
3. If further pain develops
• Reassess cause of pain and treat appropriately (see Pain Assessment top of this page)
• If there is consistent need for frequent breakthrough analgesia, and the pain is opioid sensitive, increase the total daily opioid dose by 30–50% and reassess.
• If the proposed dose increase is greater than 30 – 50% seek advice from specialist palliative care.