Use of Transdermal Fentanyl - St Elizabeth Hospice

Use of Transdermal Fentanyl
Introduction
Fentanyl is an alternative strong opioid for stable moderate to severe opioid responsive pain.
It is available as a transdermal patch with duration of action of 72 hours. Due to its long half life
Transdermal fentanyl takes 12-24 hours to reach therapeutic drug levels following application therefore it
is not appropriate to use fentanyl in patients who need rapid titration of their medication for severe
uncontrolled pain.
Indications
• Where oral or subcutaneous routes are inappropriate or unacceptable
• Poor absorption(e.g. inflammatory bowel disease, intractable nausea and vomiting)
• Dysphagia
• Intractable morphine induced constipation or other unacceptable side effects with morphine
• Compliance is poor but supervised patch application is possible
• Mild to Moderate Renal failure
Cautions
• In treatment of unstable pain
• Avoid exposure to external heat sources e.g. hot water bottles, hot baths as these may cause
increased delivery rate, resulting in toxicity
• Elderly and debilitated patients: toxicity more likely
• Fentanyl, as with all other strong opioids should be used with caution in severe liver and renal
disease.
GENERAL POINTS
• Prescribe generically stating which type of patch is being used, either matrix or reservoir. Patients
should remain on same type/brand of patch to avoid potential differences in bioavailability.
• Apply to intact normal, non-hairy skin avoiding irradiated areas, scar tissue or oedematous skin.
• Patches should be changed every 3 days applying each new patch to a different skin site.
• In a small proportion of patients the patch appears to lose efficacy after 48 hours. Usually this is
because the dose needs to be increased but a small percentage of patients do better if the patch
is changed every 2 days.
• Steady-state plasma concentrations of fentanyl are achieved after 36-48h; the patient should
therefore use prn doses of immediate release opiate during the first 3 days
• A normal release opioid e.g. oral morphine or diamorphine SC must be available prn for
breakthrough pain or to counteract any opioid withdrawal syndrome which can occur during the
fentanyl initiation period. The correct 4 hourly equivalent dose should be used (see fentanyl dose
conversion chart)
• Avoid direct contact with heat which increases drug absorption e.g. hot water bottle, electric
blanket
• Showering is possible as patches are waterproof but avoid soaking in a hot bath.
• If patch adherence is poor, use micropore tape or an adhesive dressing such as Tegaderm.
DriClor antiperspirant roll-on can be applied prior to patch application to improve adhesiveness

• Fentanyl is unsuitable for patients with marked sweating or persistent fever. Allergy to the silicone
medical adhesive may occur and necessitate change to alternative opioid.
• After removal patches should be folded firmly in half so that the adhesive is not exposed and
disposed of safely as they may contain significant residues of fentanyl.
• Fentanyl is less constipating than morphine and it may be necessary to reduce the dose of
laxatives.
• Some patients experience opioid withdrawal symptoms when changed from morphine to TD
Fentanyl despite satisfactory pain relief. These manifest with symptoms of colic, diarrhoea,
nausea, sweating and restlessness and may last for a few days; prn doses of immediate release
morphine can be used to relieve troublesome symptoms.
NB Durogesic D-Trans is superior to other fentanyl patches in terms of adhesion. It is important
to note that changing from one brand of patch to another may not be exactly equivalent in dose.
INITIATION OF FENTANYL
• Patient should be on a stable dose of strong opioid equivalent to about 30-60mg oral morphine /
24 hours before a fentanyl patch is initiated.
• Calculate the dose of fentanyl from the data sheet conversion chart below or seek advice.
FENTANYL PATCH CONVERSION CHART
4 hrly, immediate release oral morphine
dose (mg)
Fentanyl
patch dose
(micrograms/hour)
24 hour oral morphine
dose(mg)
2.5 -10 12 < 60
5 - 20 25 < 135
25 – 35 50 135 – 224
40 – 50 75 225 – 314
55 – 65 100 315 – 404
70 – 80 125 405 – 494
85 – 95 150 495 – 584
100 – 110 175 585 – 674
115 – 125 200 675 – 764
130 – 140 225 765 – 854
145 – 155 250 855 – 944
160 – 170 275 945 – 1034
175 – 185 300 1035 - 1125
• Five patch sizes are available 12, 25, 50, 75, 100 micrograms/hour.
• Patches can be combined to achieve desired dose.
• Systemic analgesic concentrations are generally reached within 12hr; so if converting from:
a. 4hrly oral morphine, give regular doses for the first 12 hr after applying the patch.
b. 12hrly m/r morphine, apply the patch and give the final m/r dose at the same time.
c. A syringe driver, continue the syringe driver for about 12hr after applying the patch.
ADJUSTING FENTANYL PATCH DOSE
• If patient shows signs of opiate toxicity e.g. drowsiness, confusion, myoclonic jerks, pinpoint
pupils, reduce the dose and reassess the pain.
• After 48 hrs, if a patient continues to need 2 or more rescue doses of morphine a day, the patch
strength should be increased by 25microgram/h. Remember it will take 12-24 hrs for the
increased dose to take effect.

USE OF TRANSDERMAL FENTANYL IN THE TERMINAL STAGES
• In moribund patients, it is best to continue the transdermal fentanyl and give rescue doses of
morphine or diamorphine calculated according to the fentanyl conversion chart.
• If >2 prn doses/24h are required consider giving morphine or diamorphine via CSCI
• In an unstable pain situation it may be necessary to remove the patch and start a syringe driver.
PLEASE SEEK SPECIALIST ADVICE
CONVERTING FROM TRANSDERMAL FENTANYL TO ORAL OPIATES
o Fentanyl is mainly excreted by hepatic metabolism to inactive metabolites but a reservoir of
fentanyl accumulates in the skin under the patch. Significant blood levels can persist for 12-24
hours after the patch is removed.
o Remove fentanyl patch but do not start the patient on regular oral morphine until 12 hours after
the patch has been removed because there will be an existing subcutaneous reservoir of
fentanyl.
o When converting from fentanyl to immediate release oral morphine use the lower dose
indicated in the range on the conversion chart to calculate the equivalent 4 hrly dose of oral
morphine. If an alternative strong opiate is being prescribed calculate the equivalent dose from
the oral opiate potency ratios guideline
o Ensure that an immediate release oral opiate e.g. morphine is prescribed prn for the first 12
hours after removing the fentanyl patch.
o 12 hours after removing the patch prescribe a regular dose oral opiate either q4hrly immediate
release morphine or modified release preparation every q12hrly.This dose can be calculated from
the fentanyl conversion chart.
CONVERTING FROM TRANSDERMAL FENTANYL TO SUBCUTANEOUS MORPHINE
1. Calculate the equivalent 24 hour oral morphine dose from the fentanyl conversion chart.
2. Use the mid dose of the range given
3. Divide this dose by 2 to calculate the dose of morphine/24 hours SC.
4. Commence CSCI 12 hours after removal of fentanyl patch
CONVERTING FROM TRANSDERMAL FENTANYL TO SUBCUTANEOUS DIAMORPHINE
1. Calculate the equivalent 24 hour oral morphine dose from the fentanyl conversion chart.
2. Use the mid-dose of the range given
3. Divide this dose by 3 to calculate the 24hour dose of diamorphine SC
4. Commence CSCI 12 hours after removal of fentanyl patch
References
1. Fentanyl TTS data sheet. Summary of product characteristics. http://www.medicines.org.uk/ Jan
2008
2. British National formulary No 54. September 2007. http://bnf.org
3. Palliative Care Formulary .third edition 2008. Twycross R + Wilcock A
4. Ahmedzai S, Brooks D. Transdermal fentanyl versus sustained release oral morphine in cancer pain;
preference, efficacy and quality of life. Journal of Pain and Symptom Management 1997;13:254-261
5. Portenoy RK, et al.Transdermal Fentanyl for cancer pain. Anaesthesiology 1993;78: 36-43
6. Fine PG. Fentanyl in the treatment of cancer pain. Seminars in Oncology .1997; 24: 20-27
7. Donner B et al. Long term treatment of cancer pain with transdermal fentanyl. Journal of Pain and
Symptom Management 1998;15: 168-175