This situation came up at work a few shifts ago. Had 20ish year old admitted for acute appendicitis. All meds IV or PR since he was NPO for surgery. Next day--surgery went great, tolerating clear liquids, doing well. C/O headache that he wants Tylenol for at 0215. That is the one med the MD didn't switch the route on, so it's only ordered PR. The pt refuses of course, so I wrote a telephone order from the MD to change it to PO. He got the Tylenol, headache went away, yay. MD comes in, sees order, says thank you for not calling me for that. I think I did okay.
I'm not prescribing/writing orders liberally or often, but some things we know how to handle.
Another nurse is freaked out by this. Everything is straight by the book for her. There is no nursing judgment or using your brain. She calls the doctor for every, stinking little thing; but then cries when the doctor gripes at her.