I know I have a nerve issue in my neck because, at one point, I was concurrently getting tingling and numbness in my thumb. This predates may back issues. I even got a strange rash on the back of my thumb that the PTs said they'd never seen. They thought it was unrelated but I thought it was more than a coincidence that it happened at the exact same spot as the tingling.
The PT gave me an exercise- external rotation using a band, when rotated outwards pinch the shoulder blades and then look up. I still do those. When I look up, it's like a switch turning on the pain in the shoulder. I can paddle long distances without much shoulder pain (in the summer when it's flat) because I keep my head down on the deck on my board most of the time.
Ibuprofen (vitamin I) works for me but I try to limit my use because it is not good for the heart. I asked my cardiologist about it and he said it's OK occasionally. He wouldn't say exactly how much is too much. I don't know if your regime, 1800mg a day for a week, would be a good idea for me.
Common pain medications such as ibuprofen or naproxen sodium may increase the risk of heart attack and stroke.
www.mayoclinic.org