Sir you haven't mentioned to which part tendonitis is causing pain. I would strongly recommend against Naprosyn 250 as it is a pain killer and on long term use can affect your kidneys.
In your condition nerve medications are very helpful and safe and should be taken on advice of a qualified pain specialist.
Next Steps
Consult with an experienced Pain Management Specialist for long term relief.
Health Tips
Don't bend forward and lift heavy weight.