Palliative care medications are targeted at symptom management and titrated according to response and PRN use. Generally, the combination of medications target pain, nausea, and agitation. The goal is not sedation of the patient though this is probably an effect of sedating medicines at higher dosages.
Subcutaneous administration
Typically, palliate medication is administered subcutaneously when the oral route is not feasible or poorly tolerated. The goal is to commence on a continuous subcutaneous infusion for control of symptoms in the end of life.
Three drug combinations
There are various three drug combinations in use for the three major symptoms (pain, nausea, and agitation). Selection of these drugs is made bases on the severity of symptoms, underlying causes, and other potential symptoms that may be treated by the selected medicines.
Common combinations include:
- Morphine/oxycodone + levomepromazine + midazolam
- Morphine/oxycodone + metaclopramide + midazolam
- Morphine/oxycodone + haloperidol + midazolam
- Morphine/oxycodone + hyoscine (scopolamine) butylbromide + midazolam
Cyclizine may also be used but it is advised that it be diluted in water for injection rather than 0.9% NaCl as for the other combinations above. Some medications are incompatible (for admixture for infusion via pump). The evidence is limited; refer to latest guidelines (or the Palliative Care Handbook).
Commencing PRN palliative care medications
Generally PRN dosing alone should be used only while awaiting implementation of a continuous infusion. Be guided by the PRN usage in a 12 or 24 hour period to calculate the total dose to administer when the continuous infusion is started.
PRN medications as below should be left on the chart for breakthrough symptoms and their use considered each time the infusion is recharted (usually each day).
Morphine
2.5-5mg quaque 4 hora pro re nata
Morphine is the drug of choice, particularly for cancer pain. It should not be used in patient with significant renal impariment.
The PRN dose for patients currently on continuous infusion is usual 1/6-1/5 of the total daily dose.
Oxycodone
1.25-2.5mg quaque 4 hora pro re nata
The PRN dose for patients currently on continuous infusion is usual 1/10-1/6 of the total daily dose.
Levomepromazine
2.5-5mg quaque 8 hora pro re nata, max 25mg in 24 hours
Haloperidol
0.5-1mg quaque 4-6 hora pro re nata, max 5mg in 24 hours (3mg in the elderly)
Midazolam
2.5-10mg quaque 4 hora pro re nata, max 60mg in 24 hours
Midazolam is usually given in combination with an antipsychotic for terminal agitation.
Hyoscine butylbromide
20mg quaue 4 hora pro re nata
Commencing continuous infusion
Continuous infusion should probably be started as soon as practical… Consider the PRN usage, or start at a low dose and titrate up.
Morphine/oxycodone + haloperidol + midazolam
- Morphine 10-20mg/24hours
- Haloperidol 1-2mg/24hours
- Midazolam 10-15mg/24hours
Morphine/oxycodone + levomepromazine + midazolam
- Morphine 10-20mg/24hours
- Levomepromazine 6.25mg/24hours
- Midazolam 10-15mg/24hours
Medication selection
Pick one from each class… All doses are for subcutaneous administration.
| Class | Medication | Indication | Starting dose 24hr | Starting dose PRN |
|---|---|---|---|---|
| Analgesic | Morphine | First choice analgesic | 10-20mg | 2.5-5mg Q4H Max 20mg |
| Oxycodone | Poor renal function | 10-20mg | 1.25-2.5mg Q4H Max 10mg | |
| Antiemetic | Haloperidol | Good for chemical causes (medications, deranged biochemistry, toxins) Good for bowel obstruction | 1mg | 0.5-1mg Q4-6H Max 3mg |
| Levomepromazine | Best for multifactorial nausea (active at multiple receptors) Can be sedating | 6.25mg | 2.5-5mg Q8H Max 15mg | |
| Metoclopramide | As for haloperidol Also good for other gastrointestinal causes (gastritis, stasis) | 30-60mg | 10mg Q6H Max 40mg | |
| Tranquliser (sedative) | Midazolam | Terminal anxiety/agitation | 10-15mg | 2.5-5mg Q4H Max 30mg |
Further reading
- New Zealand Palliative Care Handbook