I'm 79 with "extreme risk" osteoporosis and really didn't want to use prednisone, but the pain was too bad. Also was fearing the possible side condition and that the PMR might spread to my legs rather than being restricted to my upper arms and shoulders. Then I was given 15mg Prednisone, and waited. And waited. On the second day there was slight improvement in morning pain, and that was it. I'd made a bargain with the Devil, and gotten nothing from it.

It was a holiday weekend, so more than a week until I could reach my doctor. She upped the dose to 25mg on July 3rd. Next day, no change. Morning after that, there was noticeable additional flexibility and less pain. Two weeks later, I felt pretty much normal other than morning stiffness, and tapering has started. Last week I spoke to a city rheumatologist on the phone (July 27). She wants me tapering off as quickly as possible and spoke about methotrexate. But this was the thing that most surprised me. I made a comment "I guess I'll never mow the lawn again." (My assumption had been that PMR was triggered by over-doing.) Her response: "You're okay now. Go for it. Use it or lose it". At the start of the month I had to wear jeans because I couldn't handle the elastic in sweatpants. Couldn't pull up blankets. Slid out of bed because I couldn't use my arms. Oh.

So... my guess is that if you take a larger dose now, you might be done with prednisone sooner and you'd feel a whole lot better. No guarantees, of course, but right now I'm downright optimistic.