I've been struggling with lower back pain for months now. Paracetamol and ibuprofen is no longer touching it so the gp prescribed naproxen along with omneprazole. I took the first one yesterday and the first 6 hours were great, but then when it started to wear off I felt horrendous! Nausea, cold sweats, anxiety, racing heart, shivers, and terrible indigestion. I googled the side effects and it seems these are quite common along with some scarier ones like stomach ulcers and heart problems. Annoyingly, it worked brilliantly for my back but I'm not sure it's worth it for the side effects.