Long term prescribing
Choice of Drug
- Choice of opioid depends on clinical circumstance, local formularies and guidance and individual knowledge and competence.
- There is little evidence that one opioid is more effective and associated with fewer side effects than others.
- Oral morphine should be the drug of first choice.
- There is a theoretical rationale for trying an alternative opioid if the first drug tried is helpful but causes intolerable side effects.
- Pethidine is particularly unsuitable for patients with persistent pain. Its high lipid solubility and rapid onset/offset may predispose patients to problem drug use. Its active metabolite norpethidine can lead to serious central nervous system side effects. It does not produce less smooth muscle spasm than equivalent doses of other opioids and so has no advantage for patients with visceral colic or pain.
- It is helpful to calculate total daily dose of opioid in morphine equivalents, particularly when more than one opioid is used.
- Drugs should be used for their licensed indication only.
Choice of Formulation/Route
- The oral route is the preferred route of administration.
- In most settings an initial opioid trial is probably best achieved using an immediate release opioid formulation for a very short period (between one and two weeks). When choosing a formulation for an individual patient, the temporal characteristics of his/her pain should be considered and matched to the release profile of the opioid chosen.
- Use of immediate release preparations can provide effective symptomatic relief and use of such regimens may be justified when :
• the pain is intermittent and short-lived;
• pain intensity varies significantly: use of regimens including immediate release preparations allows flexibility to reduce dose on days when pain is or is expected to be less severe; or
• background pain is well controlled with modified release preparations but the patient has infrequent, short-lived episodes of increased pain.
- Modified release opioids administered at regular intervals may be more appropriate for patients with persistent pain throughout the day and night.
- Use of opioid formulations with a rapid onset, such as fentanyl for transmucosal or sublingual administration are inappropriate for the management of persistent pain,
- Injectable opioids should NOT be used in the management of patients with persistent non-cancer pain.
- For a small number of patients, the transdermal route may be a suitable alternative.
The goals of opioid therapy should be agreed between the prescriber, the patient and their carer(s). If the prescription is initiated in secondary care, the patient’s general practitioner should be in agreement with the prescribing plan. It is usually expected that a reduction in pain of at least 30% should be demonstrable to justify longer term prescribing. Functional goals should also be agreed with the patient.
Arrangements for Review
Where practicable, review of long-term opioid therapy should be carried out by the initial prescriber until an agreed long term regimen has been established the patient should be reviewed within four weeks of initiation of opioid treatment the frequency of review once the opioid regimen has been established will depend on the early effectiveness of treatment, the frequency of troublesome side effects, the timing of additional interventions to control pain (eg, surgery) and the presence of concerns in relation to problematic use of opioids. When a regimen is stable and the patient reports substantial relief of symptoms and where additional concerns do not dictate otherwise, opioid treatment should be reviewed at least six monthly.
- The ability to create computer-generated prescriptions for Controlled Drugs has made the actual process of prescribing opioids much easier and opioids may be entered into opioids onto repeat prescribing systems. However, this practice is discouraged.
- In general, opioids should not be added to the repeat prescribing system but should be generated as acute prescriptions.
- If an opioid has a demonstrable positive benefit for an individual patient and there is a robust system for monitoring use then consideration may be given for short-term authorisation of repeat prescriptions.
- The prescriber and patient together should review the continuing benefit of opioid therapy and potential harms at regular intervals (at least twice each year).
The plan for long-term prescribing should be clearly documented and if appropriate, a copy of the agreed aims of therapy and how these may be monitored should be given to the patient. Documentation should also include:
- relevant clinical findings that support the decision to prescribe opioids
- agreed outcomes of opioid therapy
- the choice of drug, formulation, dose and duration of treatment. A maximum dose of drug should be defined at initiation and this should not exceed oral morphine equivalent 120mg/day.
- the circumstances under which opioid therapy should be discontinued
- arrangements for review
- the information given to patients