Greta's Story - An end - of -
life situation where a patient using Durogesic DTrans develops increasing
unstable pain.
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1. Use the conversion chart to calculate the equivalent patch strength and breakthrough dose.
Oral morphine 70 mg / 24hours is in the Durogesic DTrans 25 mcg per hour dose range. Leave the breakthrough dose at 10 mg oral morphine as Greta’s pain is stable.
Greta's pain remains stable on the Durogesic DTrans patch and she is discharged home a few days later. She quickly settles back into her usual routine attending her local hospice once a week and having regular visits from her district nurse and GP.
After being home for a few months Greta's pain gradually worsens requiring a series of increases in her Durogesic DTrans dose. This was achieved in the following manner over a period of MONTHS.
25 mcg per hour to 37 mcg per hour
37 mcg per hour to 50 mcg per hour
50 mcg per hour to 62 mcg per hour
62 mcg per hour to 75 mcg per hour
75 mcg per hour to 100mcg per hour
100mcg per hour to 125 mcg per hour
The availability of the Durogesic DTrans 12 patch allows a more gradual titration. Her pain control becomes stable again on a dosage of 125 mcg per hour Durogesic DTrans patch.
6 weeks later Greta’s pain becomes unstable and very severe, scoring 9 out of 10 on a verbal rating scale.
Greta now needs to take breakthrough medication of normal release morphine tablets 75 mg 5 times daily.
She is also nauseated and occasionally vomiting and appears to be in the end stage of her life.
Follow these three steps
1. LEAVE THE PATCH ON at the current dose of 125 mcg / hour
If Greta's Durogesic DTrans patch was to be removed this would mean the plasma fentanyl concentration will fall slowly and introduce a decreasing level of analgesia. This will complicate the titration required to regain pain control.
The Durogesic DTrans patch must be left in place and changed as before every 3 days.
2. INITIATE SUBCUTANEOUS MORPHINE VIA A SYRINGE DRIVER
The rationale for this is that a more rapid initial response will occur as morphine levels will rapidly rise and titration to a successful morphine dose will be quicker than if the patch was increased in strength. Because Greta’s pain is uncontrolled and she is nauseated, subcutaneous morphine via a syringe driver is a more suitable mode of administration. Calculation is as follows:
| Dose of oral morphine taken in 24 hours is | (75 mg x 5) |
= 375 mg / 24 hours |
DIVIDE by 2 to convert morphine dose from oral to subcutaneous equivalent dose |
|
= 185 mg |
| Because the pain has not been controlled at this dose increase the dose by 30% (SIGN 44 recommendations) |
(30% of 185 mgs) |
= 55 mgs |
| New dose of subcutaneous morphine is |
(185 + 55) |
= 240 mgs / 24 hours |
REMEMBER
a. Continue with the Durogesic DTrans 125 mcg/hour patch
b. Discontinue the oral morphine
3. CALCULATE A NEW BREAKTHROUGH SUBCUTANEOUS DOSE AS FOLLOWS;
The NEW breakthrough dose is the sum of the breakthrough dose of the 125 mcg Durogesic DTrans patch PLUS the breakthrough dose of the 24 hour subcutaneous morphine.
Breakthrough dose of Durogesic DTrans 125 mcg / hour |
= 70-80 mgs ORAL morphine (conversion chart) Equivalent to 35-40 mg subcutaneous morphine |
Subcutaneous morphine 240 mgs in 24 hours |
= 40 mgs (1/6th of total regular 24 hour morphine dose) |
NEW breakthrough dose of subcutaneous morphine |
= 80 mgs (40 + 40) |
Hence Greta’s final prescription is now |
|
1. Durogesic DTrans patch |
= 125 mcg / hour |
2. Subcutaneous morphine infusion |
= 240 mg over 24 hour |
3. Breakthrough subcutaneous morphine dose |
= 80 mgs as needed |
Following this medication review these changes are put into effect, 24 hour support is arranged by the primary care team and Greta dies peacefully at home 5 days later.
