CMO: Fent vs. Morphine

[Femtochemistry]

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Hello;

Today in the unit, we made a patient CMO status. He was on fent drip and I decided to switch fent and start morphine drip. Nurse flips and tells me the attending prefers fent (not entirely true)--I believe she just didn't want to go through the hassle of switching pumps. Is there any benefit of morphine vs fent gtt for CMO patient? For my little experience (CA-2), morphine seems the better options. Any advice?

Cheers.👍

 

[pgg]

It doesn't matter at all, but upsetting a nurse you don't like with your choice of morphine is a worthy end in and of itself.

Is there a fentanyl shortage at your hospital? There's a reason with less spite in it ...

What were you hoping to accomplish by switching? I don't see a real advantage to morphine over fentanyl when it comes to a withdrawal-of-care infusion.

 

[Femtochemistry]

She wasn't pissed off or anything, we are good friends. My reason why I do morphine over fent is solely based on my 4 month experience in the unit--attendings seem to prefer it too. I've always used morphine and I am more comfortable with it in CMO patients. I tried google scholar and did not come up on anything earth-shattering.

 

[dhb]

What's the difference?

 

[Femtochemistry]

What's the difference?

My CCM fellow also favors morphine but I really didn't understand his explanation. Active metabolites of morphine perhaps?

 

[Doctor4Life1769]

My CCM fellow also favors morphine but I really didn't understand his explanation. Active metabolites of morphine perhaps?

What does it matter when it's end of life/CMO anyway?

 

[Idiopathic]

no appreciable difference. it isnt worth changing a pump out to give one over the other in this setting. the pain relief is equivalent, fentanyl is probably more easily titratable and has more predictable activity and fewer side effects, but i wouldnt stop morphine to start fentanyl, and vice versa.

 

[Prof Moriarty]

My understanding is:
-Fentanyl is preferred in cases of poor renal function.
-Morphine and its metabolites are 95% cleared by the kidneys. As someone mentioned, morphine-6-glucuronide is an active metabolite. In dehydration or acute/chronic renal failure with impaired renal clearance, one would either increase the dosing interval or decrease the dose to avoid accumulation.

Check this out: http://www.eperc.mcw.edu/fastFact/ff_161.htm

Re: the question about "What does it matter when it's end of life/CMO anyway?": The patient may have a few days or weeks left. Depending on the patient's/family's goals of care, symptoms can be managed aggressively and the focus turns to quality of life. How we help the patient with this phase of their life still matters and can have a significant impact on the patient and a lasting impact on family members. When you see this done correctly a few times and incorrectly a few times, it's a world of difference. I agree this particular decision is not the end-all-be-all, but we need to guard against cynicism in EOL/CMO care.

 

[epidural man]

Hello;

Today in the unit, we made a patient CMO status. He was on fent drip and I decided to switch fent and start morphine drip. Nurse flips and tells me the attending prefers fent (not entirely true)--I believe she just didn't want to go through the hassle of switching pumps. Is there any benefit of morphine vs fent gtt for CMO patient? For my little experience (CA-2), morphine seems the better options. Any advice?

Cheers.👍

My 17 cents....

It probably is just an academic discussion and in the end, probably not a big clinical difference in the case you describe.

However, here are some things to think about.

Morphine is metabolized by several enzymes (but primarily by the UGT system. This system (along with some of the P450 enzymes used to metabolize morphine) have A LOT of genetic variation that changes the pharm properties of morphine - from therapeuitc failure to toxcity. Also, the milieu the drugs are in (sepsis, etc) can change these systems a lot as well. In addition, even the transport system that brings morphine to the other side of the BBB has a lot of genetic varients. All these things give wide responses to morphine - (although I use it almost everytime I do anesthesia). Morphine also undergoes enterohepatic recycling which also makes it behave differntly in different people. Finally, opioids have active metabolites that either help with pain, or increase toxicity.

Fentanyl on the other hand, is 99% metabolized by the liver (so great drug in renal failure) and is only metabolized by cyp34a - which has less genetic variation affecting fentanyl metabolism. There are no known active metabolites of fentanyl.

I'm not sure this makes any difference in an end of life care case, but I will say that I have seen A LOT of myoclonus in end of life care cases I have been involved with - but never have seen it with fentanyl. Theoretically, it happens with all opioids.