I think the previous comment had it closer:
> but doctors and nurses aren't data entry specialists: for the most part, they... encode all the information ("Ampicillin 5mg three times daily") as free text in the medication's "Description" field.
When I worked in the field, the user interviews we did said that basically that doctors don't have time to flip through all the menus and dropdowns. Part of it is the ego that comes with a decade of med school, but part of it is that it IS legitimately faster to scrawl "Ampicillin 5mg three times daily" (or some days "5mg Amp 3x daily") on a piece of paper and move on to the next crisis.
This is the part of medicine that could benefit from the silicon valley consumer-centric design mentality. It's not that hard to build something prettier than the average piece of enterprise software. The real test is can your responsive and reactive UI make something that has the accuracy benefits of being electronic while still faster than scrawling "5mg Amp 3x daily" on paper so your user can move on to the next patient.