Hi,
If you are billing an E&M code on the same visit as 94664 I would recommend using the 25 modifier on the E&M code. 25 modifier states:
Significant, Separately Identifiable E&M Service by the Same Physician on the Same Day of the Procedure or Other Service:
You should also bill for the drugs separately. Each insurance company will process them according to their own guidelines, some may pay, some may bundle.
Michele