Lots of opioid conversion tables and calculators out there, but all that I have found have limited selections and most are very clumsy. Is there a better one out there with a decent selection of opiates and delivery methods? Morphine ER, fentanyl transdermal and IV, oxy IR and ER, and so on?
The GlobalRPH calculator is the best one I've found.
Posted Jan 2, 2019, 1:28 PM UTC
FWIW, The advice I usually give clinicians in training is this: most people who are not specialists will primarily be using morphine, oxycodone, and Dilaudud. The equianalgesic calculations for these medications are pretty linear and are a one step algebra operation. Do it yourself and then check your work with these tools, but never trust them blindly. I’ve witnessed physicians cause harm to patients because these online calculators were programmed incorrectly. If you don’t remember your basic algebra: you should never hesitate to call the pharmacist, pain management physician, or friendly neighborhood palliative medicine team.
most people who are not specialists will primarily be using morphine, oxycodone, and Dilaudud
And hydrocodone. And in the hospital, fentanyl.
Still easy enough to remember.
True. And another good point. I definitely should have included hydrocodone. Fentanyl conversions can get screwy though, especially when using IV and then needing to go to a transdermal formulation. I always try and encourage my trainees to get in the habit of asking for help. It’s better not to try and pretend all of us can know everything.
That's a fair point, but not accurate in rural areas. And no you can't blindly switch, but it's amazing how often I do need to switch.
That is an excellent point.
Understanding, of course, that opiates cannot generally be blindly converted by equianalgesic dosage, but a decent calculator helps quite a bit to establish a general guide.
I found this one when I was working with my local hospice http://book.pallcare.info/index.php?op=plugin&src=opiconv
There's an Android app called Opioid Converter that uses the data from GlobalRPH. There's an easy interface and it let's you correct for incomplete cross tolerance. It's missing intrathecal/epidural conversions, but otherwise its pretty solid.
If you have Medscape they have a pretty good opioid conversion section with tables
This calculator on iOS (Opioids Dosage Conversion) is pretty solid as well. It has the same functionality as the PPM website in an app.
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I’ve used this one from practical pain management and have liked it.
I liked it cause it tells you the doses recommended, the duration and all that good stuff.
That one is by Jeff Fudin, a very experienced clinical pharmacist. If you look into the methadone calculation, you will find quite a lot behind how they came up with the equation. The equation has trigonometric functions in it (cosine etc) because of the "sawtooth" pattern of the equianalgesic conversion, and to interpolate in a somewhat linear fashion, angles of the triangles between peaks of the curve have to be calculated.
GlobalRph eventually updated their methadone conversion to Practical Pain Management's.
That is precisely what I was looking for but didn't have the words to describe, thank you.