Conversion of an Oral Morphine Dose to a Transdermal Fentanyl Patch Strength

A patient on long-term oral morphine therapy can be converted to transdermal fentanyl therapy.

Patient selection: opioid tolerant. Transdermal fentanyl must not be used for an opioid-naïve patient.

For the patch strength used in the USA and UK:

Daily Dose of Oral Morphine in mg	Fentanyl Patch Delivery in µg per hour
< 45	NA
45 to 134	25
135 to 224	50
225 to 314	75
315 to 404	100
405 to 494	125
495 to 584	150
585 to 674	175
675 to 764	200
765 to 854	225
855 to 944	250
945 to 1025	275
1035 to 1124	300
> 1124	NA

For the patch used in Germany the conversion is (Muijsers et al):

Daily Dose of Oral Morphine in mg	Fentanyl Patch Delivery in µg per hour
0 to 90	25
91 to 150	50
151 to 210	75
211 to 270	100
for every additional 60 mg	another 25 µg/h

fentanyl patch strength in mg=

= (fentanyl delivery in µg per hour) / 10

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