Currently, there is no drug-allergy or drug-drug interaction warning when adding an external medication to a patient that has a known allergy or active prescription for it already saved on the chart.
However, there is an allergy warning if you add the external medication first, then the allergy.
There also is an allergy warning if you renew an external medication, just not when first putting it in.
Users are expecting this section to function the same as the active prescriptions area as providers still need to know about interactions when recording medications prescribed elsewhere.
This has been completed in builds:
2017.01.68
2016.04.78
It is not possible to back-merge past 2016.04