Morphine or Diamorphine* prescribing at the end of life
Morphine or diamorphine are frequently prescribed in the in the last few days of life. In the wake of the Shipman trial it is even more important for patients, families and the general practitioner and primary health care team to be confident they are being prescribed correctly. This means prescribing appropriate and defensible doses for appropriate and documented indications. Clear discussion with the patient and the family about the indication and dosage is vital.
Morphine and diamorphine are primarily a strong analgesics. They are cough suppressants and in the absence of pain are respiratory sedatives. This side effect can be utilised to relieve distressing breathlessness at the end of life.
Morphine and diamorphine are NOT a strong sedatives. They are generally unsuitable for terminal agitation, anguish or distress and if used inappropriately, it may cause or exacerbate these problems. In the absence of pain or in excessive doses morphine or diamorphine can cause nightmares, hallucinations, sweating, confusion and myoclonic jerks. If a patient needs sedation, benzodiazepines are a better choice.
| Clinical situation at the end of life | Subcutaneous (S/C) morphine dose over 24 hours |
As requiredsubcutaneous (S/C) morphine dose |
|
No previous opioid No pain |
Not indicated | 5-10mg S/C prn |
|
No previous opioid In pain |
20-30mg/24 hours (Halve dose if less than 70 years or frail) | 5-10mg S/C prn |
|
On oral morphine No pain |
Oral morphine dose in mg/24 hours divided by TWO | One sixth 24 hour dose in mg S/C |
|
On oral morphine In pain |
Oral morphine dose in mg/24 hours INCLUDING BREAKTHROUGH DOSES divided by two | One sixth 24 hour dose in mg S/C |
Sometimes if a patient is in severe pain and near death, it can be tempting to put a much larger dose of morphine or diamorphine in the syringe driver. This is unsatisfactory for two reasons:
- Morphine or diamorphine from a syringe driver takes about four hours to build up to a steady plasma level so is not quick enough.
- It is very difficult to guess the correct dose, particularly in a patient who has not had opioids before. Too little and the patient is still in pain, too much and the patient may die from an opioid overdose. With severe pain it is better to prescribe a safe and defensible dose of diamorphine in the syringe driver, following the guidance above, and to give "as required" doses every hour or so to quickly gain both pain control and a sense of the correct 24-hour requirement.
* NHS Cumbria recommends morphine as the first line parenteral strong opioid for palliative care patients. For high doses (>morphine 180mg/24h SC) use diamorphine, which is more soluble.
© Dr. Eileen Palmer, Dr John Howarth Palliative Care for the Primary Health Care Team Quay Books ISBN 1856422291