On removal of the patch, it takes approximately 17 hours for serum concentration of fentanyl to reduce by 50%.
Different methods of conversion are practised. The preferred methods A and B according to pain control, are given below:
A. Discontinuing the patch if the patient's pain is controlled either
- Change to oral opioid
- remove patch and document the time of removal
- prescribe a starting dose of oral opioid at the approximate equivalent dose (for that patch) to be commenced 12 hours after the time the patch has been removed
- ensure adequate dose of oral immediate release opioid is available p.r.n. for breakthrough pain
- OR
- change to subcutaneous opioid e.g. diamorphine or morphine or oxycodone infusion:
- remove patch and document the time of removal
- prescribe a starting dose of subcutaneous opioid over 24 hours at the approximate equivalent dose (for that patch) to be commenced 12 hours after the time the patch has been removed
- ensure adequate dose of subcutaneous opioid is available p.r.n. for breakthrough pain
B. Discontinuing the patch if the patient's pain is uncontrolled, consider seeking specialist advice
- consider why the pain was not responding and address any other issues
- consider seeking specialist palliative care advice
- administer an immediate release opioid (e.g. p.r.n. oral morphine or SC opioid). Re-titrate to the patient's requirements
- review the patient regularly during this change over period
If converting a patient with renal failure from transdermal fentanyl to an alternative opioid then seek specialist advice.
Continuing the patch if the patient's pain is uncontrolled:
- add an appropriate increment of opioid by the subcutaneous route whilst continuing the patch
- in some areas, it is practice to continue with fentanyl patch administration, adding an appropriate dose of opioid via the subcutaneous route. Consult local guidelines
Note (1): in the last days of life it may be acceptable practice in some cases to continue with fentanyl patch administration, adding an appropriate increment of diamorphine by subcutaneous infusion - seek specialist advice in this situation
Reference:
- West Midlands Palliative Care Physicians (2007). Palliative care - guidelines for the use of drugs in symptom control.
- West Midlands Palliative Care Physicians (2012). Palliative care - guidelines for the use of drugs in symptom control