The anesthetic charts and flowsheets are not linked as this avoids showing too many meds on the charts, but you could make a new line in ‘medication’ or ‘procedure’ fields and add them there. 

For example:
 Under procedures: add premedication (see blue circle & arrow on fig. below)

Then you could make a procedure called Intra-op meds (or similar), where any other meds could be written in the comments and appear on the timeline. (Red circle and arrows in figure).