The QTY for a 90-day supply is undetermined by: David
The prescriber needs to indicate how much of the medication needs to be applied and massaged into the affected area(s), as well as how large the affected area(s) are. If you know how large the affected area is, you can determine the FTU's that will be used with each application. FTU's are FingerTip Units. If you know how much is to be applied (if this is provided by the prescriber) then you can easily calculate the days supply like you usually would. You can review FingerTip Units from a link on my Days Supply page. This page will be updated with a link to that page below.
Patient is prescribed 10g of Glucose. The glucose is presented as a 5% solution in 500ml Saline. How much of the 5% dextrose saline solution do you need