Stream: Medication
Topic: dividedDoses
Jefferson (Jul 17 2019 at 16:50):
Looking at https://www.hl7.org/fhir/medicationrequest.html I dont see any dividedDoses field. I was looking for a flag to denote that the recommended amount of medication should be divided into multiple administrations. Something like 500 – 1,000 mg/day (starting dose, adjust based on efficacy and tolerability to a maximum of 2,000 mg/day) divided into 1 – 4 daily doses PO on Days 1 – 28
Jean Duteau (Jul 17 2019 at 16:57):
I've never seen a dosing line like that. Is the 500 expected to be given over 1-4 daily doses? Or is it 1 dose of 500 given up to 4 times a day?
Jefferson (Jul 17 2019 at 17:02):
1 dose of 500 given up to 4 times a day.
Jefferson (Jul 17 2019 at 17:09):
What is there another ways you seen it?
Jean Duteau (Jul 17 2019 at 17:10):
MedicationRequest.dosageInstruction.dosage.dosageAndRate.doseRange = 500mg - 1000mg
MedicationRequest.dosageInstruction.timing.frequency = 1
MedicationRequest.dosageInstruction.timing.frequencyMax = 4
MedicationRequest.dosageInstruction.timing.period = 1
MedicationRequest.dosageInstruction.timing.periodUnit = d
MedicationRequest.dosageInstruction.timing.boundsDuration = 28 days
MedicationRequest.dosageInstruction.maxDosePerPeriod = 2000mg / 1 day
MedicationRequest.dosageInstruction.additionalInstruction.text = "starting dose of 500mg, adjust based on efficacy and tolerability to a maximum of 2,000 mg/day"
Jean Duteau (Jul 17 2019 at 17:12):
This is effectively saying "take 500mg-1000mg at a time 1-4 times a day, with no more than 2000 mg in one day for 28 days". I think that is equivalent to what you wrote.
Jefferson (Jul 17 2019 at 17:12):
Thanks
Jefferson (Aug 09 2019 at 16:57):
@Jean Duteau the 1 to 4 times a day is still saying take 500 mg each time that is the way I would read this.
Jean Duteau (Aug 09 2019 at 17:23):
Yes. That was what I was asking and I read your answer as wanting that. What I gave you is:
take 500mg-1000mg at a time 1-4 times a day, with no more than 2000 mg in one day for 28 days
each dose is 500-1000mg.
Jefferson (Aug 09 2019 at 17:35):
(deleted)
Jefferson (Aug 09 2019 at 17:35):
Sorry that was my mistake
Jean Duteau (Aug 09 2019 at 17:36):
Right, so you may not have understood my question. We don't have the ability to easily represent "divided into" in the Dosage datatype.
Jefferson (Aug 09 2019 at 17:38):
So I would need to use a extension for something like this?
Jean Duteau (Aug 09 2019 at 17:42):
Either an extension or fall back onto text. I've added a text element to indicate that the dose amount is divided into the daily doses. I've also added a maxDosePerAdministration. This is probably the best we can do.
MedicationRequest.dosageInstruction.dosage.dosageAndRate.doseRange = 500mg - 1000mg
MedicationRequest.dosageInstruction.dosage.text = "Divide the dose amount into the daily doses"
MedicationRequest.dosageInstruction.timing.frequency = 1
MedicationRequest.dosageInstruction.timing.frequencyMax = 4
MedicationRequest.dosageInstruction.timing.period = 1
MedicationRequest.dosageInstruction.timing.periodUnit = d
MedicationRequest.dosageInstruction.timing.boundsDuration = 28 days
MedicationRequest.dosageInstruction.maxDosePerPeriod = 2000mg / 1 day
MedicationRequest.dosageInstruction.maxDosePerAdministration = 500mg
MedicationRequest.dosageInstruction.additionalInstruction.text = "starting dose of 500mg divided between 1-4 doses/day, adjust based on efficacy and tolerability to a maximum of 2,000 mg/day"
I've never seen a system that had this "divided into" functionality.
Jefferson (Aug 09 2019 at 17:43):
Ok thanks for the help
Jefferson (Aug 19 2019 at 18:28):
@Jean Duteau how do you handle exponents like within Text like platelet recovery >50x10^9/L following each cycle of induction
Jean Duteau (Aug 19 2019 at 20:30):
I'm not sure I understand your question. In text, you would just represent it the way you did in the chat. Where else would you want to represent it?
Melva Peters (Aug 20 2019 at 04:23):
@Tom MCDEVITT is your example about platelet recovery a condition for the dose? Like give or don’t give a dose until... if so we have a draft extension for conditional dosing. We’re looking for examples to test the extension.
Jefferson (Aug 20 2019 at 12:20):
@Melva Peters Yes it is a condition for the dose, you need to wait until the platelet count before the 21-day cycle
Melva Peters (Aug 23 2019 at 17:48):
We have published an extension in the current build for conditional doses. We're looking for examples to test the extension so would appreciate if you could have a look and see if your platelet count use case can be handled by this extension: http://build.fhir.org/extension-dosage-conditions.html
Last updated: Apr 12 2022 at 19:14 UTC
