For the most part, medications are generally billed per mL for injectable, or per tablet, or capsule for oral medication. But what about those medications that are billed slightly differently, like insulin, that are billed per unit instead of mL. 

For most drugs, when you are setting them up and "mapping" them in the Parameters section of the Settings, you usually put in the concentration of the drug as mg/ml:

The second box (/mL) is what the item will be billed as, as Smart Flow is set up to interpret data as the first box is "unit to calculate dosage" and the second box is "unit to bill."

1. If your clinic doses for IU/kg as well as bills per IU, then it needs to be put in Smart Flow as IU/IU:

You will need to set up the dosing so it is 1 IU/IU.  

When the medication is used on the patient flow sheet, the staff will still be able to calculate how many IU per kg as seen here:

However, as a side note the first boxes (IU) must always be the same as each other, otherwise it cannot calculate dose and grey's out the boxes below, as seen here:

2. If your clinic doses for IU/kg, and you bill for how many mL's were given to a patient, then you can set it up in the standard way of IU/ml:

It will show up on the patient flow sheet the same way other medications come up and Smart Flow will bill for per mL.