If his doctors were administering Dexamethasone, a heavy duty steroid, it’s wasn’t prophylacticly. That’s not a precautionary drug.
“Nicholas Christakis, a physician and sociologist at Yale University, said ‘Either he is sicker than they have let on and clearly warrants dexamethasone, or he’s not so sick, and therefore putting him on dexamethasone is irresponsible.’”
https://www.theguardian.com/us-news/2020/oct/04/donald-trumps-steroid-covid-treatment-adds-to-confusion-over-health