IV fentanyl conversion

[GottaHaveIt]

Do any of you have a conversion factor for IV fentanyl to oral morphine equivalents?

I was able to find a couple but they are not consistent so I figured I'd ask the board.

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[Ducttape]

I still use this calculator for complicated conversions:

Opioid Conversion Calculator Morphine equivalents -Advanced

Opioid equivalent doses calculator. Opioid conversions based on equianalgesia -potency for all of the common opioids hydrocodone, oxycodone, morphine, etc

globalrph.com

question - why are you making such a conversion in the first place? hopefully you do not have someone who is living on chronic iv fentanyl...

 

[kstarm]

I have used 100mcg of IV fentanyl is 15-30mg of oral morphine. Opioid conversions are more than just math especially the IV to oral conversions. More details about the case would lead to a more accurate recommendation

 

[Ferrismonk]

100mcg IV fentanyl = 10mg IV morphine = 30mg PO morphine. Of course the whole concept of conversions is just an estimate and when rotating drugs you should drop the dose to account for incomplete cross tolerance.

 

[GottaHaveIt]

Just a general question for inpatient consults as well as knowing how much I am actually giving when administering IV sedation for more involved cases.

I like the conversion posted above by Ferrismonk, simple and easy to remember.

I also use the global rph calculators frequently. That is where I saw different conversions. The single-agent calculator tells me 100mcg (0.1mg) is 30 OME and the advanced calculator tells me 12 OME.

Thanks for all the replies thus far.

 

[Ducttape]

are you anesthesia trained?

don't bother with conversions if you are using it for conscious sedation.


from an anesthesia stand point, we are brilliant compared to other specialties. keep it simple. it is always 50mcg/ml. vials are 100mcg, 250 mcg or 1000 mcg. I suspect most ASCs will primarily stock the 100 mcg vials (2 ml) and nurses will freak out if you ask them to grab a 250 mcg (5 ml) vial.

for conscious sedation, its probably easiest to tell your RN to grab 100-200 mcg (1-2 vials of the 100 mcg), and depending in age and size, 50 mcg if old and frail, 100 mcg for most (or, 1-2 ml).

re-dose 50 mcg at a time.

if you want to intubate, grab a 250 mcg vial, and give 5 ml.

for inpatient consults, i wouldnt use iv dosing to determine what they should get orally. remember that IV fentanyl is very short acting.

fyi: yes 100 mcg fentanyl is ~10 mg iv morphine, according to FDA.

https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/016619s034lbl.pdf