Pain is common in advanced cancer. About 5% of patients have pain at diagnosis and 60% at death. Most patients can be pain free, however if they are assessed fully and appropriate treatment is implemented. But some patients still suffer pain needlessly. Clinicians may often be anxious about giving an adequate dose of strong opioids such as morphine. This brief outline is intended to make the principles of pain control readily available to all clinicians who look after terminally ill patients. It applies to patients with non-malignant disease as well as to those with advanced cancer.

The principles of using morphine are identical to those for many other drugs, such as cytotoxic drugs, which also have potentially life-threatening side effects. The risk of serious adverse effects must always be weighed against the potential benefit of good pain relief in each individual.

Many patients become aware that they are dying before the clinicians caring for them. It is always difficult to predict when death will occur, but in the absence of an apparently reversible cause, patients with incurable illness will usually have a short prognosis that show.

• Progressive weight loss
• Profound weakness
• Drowsiness and reduced cognition
• Diminished intake of food and fluids
• Difficulty swallowing medication

The goals of management of a dying patient are:

• To control the patient’s symptoms
• To make the quality of life as good as possible
• To enable the patient to do what he or she wants to do

As in all clinical situations, one starts with a careful assessment. Inadequate pain assessment has been shown to be a barrier to the effective management of cancer pain. Pain can be described as "what the experiencing person says it is, existing wherever he says it does". There is evidence that pain scores given by carers (professional and non-professional) can vary significantly from patient scores.

The clinician should determine the likely reason for the pain, and whether it is reversible. However, many terminally ill patients need regular pain medication to achieve pain control.

The WHO analgesic ladder is a helpful guide when adjusting analgesia to match the patient’s pain.

Step 1 : non-opioid analgesia, e.g. paracetamol
Step 2 : opioid for mild to moderate pain, e.g. dihydrocodeine
Step 3 : opioid for moderate to severe pain, e.g. morphine

If the patient’s pain is not controlled on Steps 1 or 2, he or she needs to climb to the next step of the ladder.

Opioids, and particularly morphine, are the mainstay of management of severe pain in terminally ill patients. Many doctors and patients are anxious about using morphine. When used to treat severe pain, morphine,

• Is not addictive
• Is safe when titrated against the patient’s pain
• Has not been shown to shorten the life of dying patients

Although patients do not become addicted, as with many other drugs there may be symptoms if morphine is withdrawn abruptly. These have to be anticipated and managed carefully.

There are three not uncommon situations when this may occur.

1. Increasing the morphine dose, does not improve the pain, but does produce worse side effects.
   
   Treatment is likely to involve adding an adjuvant drug, such as a NSAID for bone pain, or anti-depressant or anti-epileptic drug for neuropathic pain. Cancer patients may respond to radiotherapy.
   
2. Increasing the morphine dose does improve the pain, but the side effects, even specifically treated, are intolerable.
   
   Delirium may be the most distressing side effect of opioid treatment.
   
3. The patient seems in total pain, because other problems make the patient distressed, and unable to deal with the pain.
   
   The problems may be psychological or spiritual, or may be physical.

• Other physical symptoms, e.g. nausea or a sore mouth, should receive equally careful assessment and management.
• Depression or extreme anxiety can be missed in the setting of severe physical illness but should be appropriately treated.
• Difficulties with family relationships or spiritual anxieties may cause great distress.

• Transdermal, e.g. fentanyl
• Others: Patients may require; chemotherapy, radiotherapy, bisphosphonates, epidural or intrathecal infusion, coeliac plexus block, cordotomy and transcutaneous electrical nerve stimulation (TENS)

Careful opioid titration is likely to produce good pain control in about 80% of patients. However, if the pain is complex or proving difficult to control, or the patient needs adjuvant treatments, one may well need specialist help to find the optimal regimen.